MTConnectError_2.3.xsd

<?xml version='1.0' encoding='UTF-8'?>
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<xs:schema xmlns:xs='http://www.w3.org/2001/XMLSchema' xmlns='urn:mtconnect.org:MTConnectError:2.3' xmlns:mt='urn:mtconnect.org:MTConnectError:2.3' targetNamespace='urn:mtconnect.org:MTConnectError:2.3' elementFormDefault='qualified' attributeFormDefault='unqualified' xmlns:vc='http://www.w3.org/2007/XMLSchema-versioning' vc:minVersion='1.1'>
  <xs:element name='MTConnectError' type='MTConnectErrorType'>
    <xs:annotation>
      <xs:documentation>
        root entity of an {{term(MTConnectErrors Response Document)}} that
        contains the {{term(Error Information Model)}}.
        ![MTConnectError](figures/MTConnectErrors.png
        &quot;MTConnectError&quot;){: width=&quot;0.8&quot;} &gt; Note:
        Additional properties of {{block(MTConnectError)}} **MAY** be defined
        for schema and namespace declaration. See {{sect(Schema and Namespace
        Declaration Information)}} for an {{term(XML)}} example.
      </xs:documentation>
    </xs:annotation>
  </xs:element>
  <xs:simpleType name='SenderType'>
    <xs:annotation>
      <xs:documentation>
        The sender of the message
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='CreationTimeType'>
    <xs:annotation>
      <xs:documentation>
        The date and time the document was created
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:dateTime'/>
  </xs:simpleType>
  <xs:simpleType name='SequenceType'>
    <xs:annotation>
      <xs:documentation>
        A sequence number
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:integer'>
      <xs:minInclusive value='1'/>
      <xs:maxExclusive value='18446744073709551615'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='TestIndicatorType'>
    <xs:annotation>
      <xs:documentation>
        A debugging flag for testing.
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:boolean'/>
  </xs:simpleType>
  <xs:simpleType name='InstanceIdType'>
    <xs:annotation>
      <xs:documentation>
        The instance number of the agent, used for fault tolerance
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:integer'>
      <xs:minInclusive value='1'/>
      <xs:maxExclusive value='18446744073709551615'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='BufferSizeType'>
    <xs:annotation>
      <xs:documentation>
        The size of the agents buffer
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:integer'>
      <xs:minInclusive value='1'/>
      <xs:maxExclusive value='4294967295'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='TimestampType'>
    <xs:annotation>
      <xs:documentation>
        The time the sample was reported
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:dateTime'/>
  </xs:simpleType>
  <xs:simpleType name='OccurrenceTimeType'>
    <xs:annotation>
      <xs:documentation>
        The time a sample occurred
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:dateTime'/>
  </xs:simpleType>
  <xs:simpleType name='VersionType'>
    <xs:annotation>
      <xs:documentation>
        A version number
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:NMTOKEN'/>
  </xs:simpleType>
  <xs:simpleType name='NameType'>
    <xs:annotation>
      <xs:documentation>
        A short name for any element
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='UuidType'>
    <xs:annotation>
      <xs:documentation>
        A universally unique id that uniquely identifies the element for
        it&apos;s entire life
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='SerialNumberAttrType'>
    <xs:annotation>
      <xs:documentation>
        A serial number for a piece of equipment
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='ItemSourceType'>
    <xs:annotation>
      <xs:documentation>
        The measurement source
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='RateType'>
    <xs:annotation>
      <xs:documentation>
        A sample rate in milliseconds per sample
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:float'/>
  </xs:simpleType>
  <xs:simpleType name='ComponentIdType'>
    <xs:annotation>
      <xs:documentation>
        The id of the component (maps to the id from probe)
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:ID'/>
  </xs:simpleType>
  <xs:simpleType name='IDType'>
    <xs:annotation>
      <xs:documentation>
        An identifier
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:ID'/>
  </xs:simpleType>
  <xs:simpleType name='SignificantDigitsValueType'>
    <xs:annotation>
      <xs:documentation>
        The number significant digits
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:integer'/>
  </xs:simpleType>
  <xs:simpleType name='CompositionIdType'>
    <xs:annotation>
      <xs:documentation>
        The item&apos;s reference to the Device model composition
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:NMTOKEN'/>
  </xs:simpleType>
  <xs:simpleType name='DurationTimeType'>
    <xs:annotation>
      <xs:documentation>
        A length of time in seconds
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:float'/>
  </xs:simpleType>
  <xs:simpleType name='RemovedType'>
    <xs:annotation>
      <xs:documentation>
        A flag indicating the item has been removed
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:boolean'/>
  </xs:simpleType>
  <xs:simpleType name='KeyType'>
    <xs:annotation>
      <xs:documentation>
        The key for adata set
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:NMTOKEN'/>
  </xs:simpleType>
  <xs:simpleType name='DeviceModelChangeTimeType'>
    <xs:annotation>
      <xs:documentation>
        A timestamp in 8601 format of the last update of the Device information
        for any device
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:dateTime'/>
  </xs:simpleType>
  <xs:simpleType name='AssetIdType'>
    <xs:annotation>
      <xs:documentation>
        The unique id of the asset
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='AssetAttrTypeType'>
    <xs:annotation>
      <xs:documentation>
        An asset type
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='AssetBufferSizeType'>
    <xs:annotation>
      <xs:documentation>
        The maximum number of assets
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:integer'>
      <xs:minInclusive value='1'/>
      <xs:maxExclusive value='4294967295'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='AssetCountAttrType'>
    <xs:annotation>
      <xs:documentation>
        The number of assets
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:integer'>
      <xs:minInclusive value='0'/>
      <xs:maxExclusive value='4294967295'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='HashType'>
    <xs:annotation>
      <xs:documentation>
        condensed message digest from a secure one-way hash function.
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='LimitValueType'>
    <xs:annotation>
      <xs:documentation>
        The limit of a value
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:float'/>
  </xs:simpleType>
  <xs:simpleType name='FloatListValueType'>
    <xs:annotation>
      <xs:documentation>
        Common floating point sample value
      </xs:documentation>
    </xs:annotation>
    <xs:list>
      <xs:simpleType>
        <xs:restriction base='xs:float'/>
      </xs:simpleType>
    </xs:list>
  </xs:simpleType>
  <xs:simpleType name='ThreeSpaceValueType'>
    <xs:annotation>
      <xs:documentation>
        A three dimensional value &apos;X Y Z&apos; or &apos;A B C&apos;
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='FloatListValueType'>
      <xs:maxLength value='3'/>
      <xs:minLength value='3'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DescriptionTextType'>
    <xs:annotation>
      <xs:documentation>
        A description
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='DataItemEnumExtType'>
    <xs:annotation>
      <xs:documentation>
        Extended tyoe for The types of measurements available
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:pattern value='[a-ln-z][a-z]*:[A-Z_0-9]+'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DataItemEnumEnum'>
    <xs:annotation>
      <xs:documentation>
        The types of measurements available
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:enumeration value='ACCELERATION'>
        <xs:annotation>
          <xs:documentation>
            positive rate of change of velocity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACCUMULATED_TIME'>
        <xs:annotation>
          <xs:documentation>
            accumulated time for an activity or event.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AMPERAGE'>
        <xs:annotation>
          <xs:documentation>
            strength of electrical current. **DEPRECATED** in *Version 1.6*.
            Replaced by `AMPERAGE_AC` and `AMPERAGE_DC`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ANGLE'>
        <xs:annotation>
          <xs:documentation>
            angular position.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ANGULAR_ACCELERATION'>
        <xs:annotation>
          <xs:documentation>
            positive rate of change of angular velocity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ANGULAR_VELOCITY'>
        <xs:annotation>
          <xs:documentation>
            rate of change of angular position.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AXIS_FEEDRATE'>
        <xs:annotation>
          <xs:documentation>
            feedrate of a linear axis.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CAPACITY_FLUID'>
        <xs:annotation>
          <xs:documentation>
            fluid capacity of an object or container.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CAPACITY_SPATIAL'>
        <xs:annotation>
          <xs:documentation>
            geometric capacity of an object or container.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CONCENTRATION'>
        <xs:annotation>
          <xs:documentation>
            percentage of one component within a mixture of components.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CONDUCTIVITY'>
        <xs:annotation>
          <xs:documentation>
            ability of a material to conduct electricity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CUTTING_SPEED'>
        <xs:annotation>
          <xs:documentation>
            speed difference (relative velocity) between the cutting mechanism
            and the surface of the workpiece it is operating on.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DENSITY'>
        <xs:annotation>
          <xs:documentation>
            volumetric mass of a material per unit volume of that material.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEPOSITION_ACCELERATION_VOLUMETRIC'>
        <xs:annotation>
          <xs:documentation>
            rate of change in spatial volume of material deposited in an
            additive manufacturing process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEPOSITION_DENSITY'>
        <xs:annotation>
          <xs:documentation>
            density of the material deposited in an additive manufacturing
            process per unit of volume.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEPOSITION_MASS'>
        <xs:annotation>
          <xs:documentation>
            mass of the material deposited in an additive manufacturing process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEPOSITION_RATE_VOLUMETRIC'>
        <xs:annotation>
          <xs:documentation>
            rate at which a spatial volume of material is deposited in an
            additive manufacturing process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEPOSITION_VOLUME'>
        <xs:annotation>
          <xs:documentation>
            spatial volume of material to be deposited in an additive
            manufacturing process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DISPLACEMENT'>
        <xs:annotation>
          <xs:documentation>
            change in position of an object.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ELECTRICAL_ENERGY'>
        <xs:annotation>
          <xs:documentation>
            {{block(Wattage)}} used or generated by a component over an interval
            of time.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='EQUIPMENT_TIMER'>
        <xs:annotation>
          <xs:documentation>
            amount of time a piece of equipment or a sub-part of a piece of
            equipment has performed specific activities.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FILL_LEVEL'>
        <xs:annotation>
          <xs:documentation>
            amount of a substance remaining compared to the planned maximum
            amount of that substance.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FLOW'>
        <xs:annotation>
          <xs:documentation>
            rate of flow of a fluid.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FREQUENCY'>
        <xs:annotation>
          <xs:documentation>
            number of occurrences of a repeating event per unit time.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GLOBAL_POSITION'>
        <xs:annotation>
          <xs:documentation>
            position in three-dimensional space. **DEPRECATED** in Version 1.1.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LENGTH'>
        <xs:annotation>
          <xs:documentation>
            length of an object.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LEVEL'>
        <xs:annotation>
          <xs:documentation>
            level of a resource. **DEPRECATED** in *Version 1.2*. See
            `FILL_LEVEL`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LINEAR_FORCE'>
        <xs:annotation>
          <xs:documentation>
            {{term(force)}} applied to a mass in one direction only.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LOAD'>
        <xs:annotation>
          <xs:documentation>
            actual versus the standard rating of a piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MASS'>
        <xs:annotation>
          <xs:documentation>
            mass of an object(s) or an amount of material.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PATH_FEEDRATE'>
        <xs:annotation>
          <xs:documentation>
            feedrate for the axes, or a single axis, associated with a
            {{block(Path)}} component.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PATH_FEEDRATE_PER_REVOLUTION'>
        <xs:annotation>
          <xs:documentation>
            feedrate for the axes, or a single axis.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PATH_POSITION'>
        <xs:annotation>
          <xs:documentation>
            position of a control point associated with a {{block(Controller)}}
            or a {{block(Path)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PH'>
        <xs:annotation>
          <xs:documentation>
            acidity or alkalinity of a solution.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='POSITION'>
        <xs:annotation>
          <xs:documentation>
            point along an axis in a {{term(cartesian coordinate system)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='POWER_FACTOR'>
        <xs:annotation>
          <xs:documentation>
            ratio of real power flowing to a load to the apparent power in that
            AC circuit.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PRESSURE'>
        <xs:annotation>
          <xs:documentation>
            force per unit area measured relative to atmospheric pressure.
            Commonly referred to as gauge pressure.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS_TIMER'>
        <xs:annotation>
          <xs:documentation>
            amount of time a piece of equipment has performed different types of
            activities associated with the process being performed at that piece
            of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RESISTANCE'>
        <xs:annotation>
          <xs:documentation>
            degree to which a substance opposes the passage of an electric
            current.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ROTARY_VELOCITY'>
        <xs:annotation>
          <xs:documentation>
            rotational speed of a rotary axis.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SOUND_LEVEL'>
        <xs:annotation>
          <xs:documentation>
            sound level or sound pressure level relative to atmospheric
            pressure.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SPINDLE_SPEED'>
        <xs:annotation>
          <xs:documentation>
            rotational speed of the rotary axis. **DEPRECATED** in *Version
            1.2*. Replaced by `ROTARY_VELOCITY`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='STRAIN'>
        <xs:annotation>
          <xs:documentation>
            amount of deformation per unit length of an object when a load is
            applied.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TEMPERATURE'>
        <xs:annotation>
          <xs:documentation>
            degree of hotness or coldness measured on a definite scale.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TENSION'>
        <xs:annotation>
          <xs:documentation>
            force that stretches or elongates an object.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TILT'>
        <xs:annotation>
          <xs:documentation>
            angular displacement.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TORQUE'>
        <xs:annotation>
          <xs:documentation>
            turning force exerted on an object or by an object.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VELOCITY'>
        <xs:annotation>
          <xs:documentation>
            rate of change of position of a {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VISCOSITY'>
        <xs:annotation>
          <xs:documentation>
            fluid&apos;s resistance to flow.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLTAGE'>
        <xs:annotation>
          <xs:documentation>
            electrical potential between two points. **DEPRECATED** in *Version
            1.6*. Replaced by `VOLTAGE_AC` and `VOLTAGE_DC`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLT_AMPERE'>
        <xs:annotation>
          <xs:documentation>
            apparent power in an electrical circuit, equal to the product of
            root-mean-square (RMS) voltage and RMS current (commonly referred to
            as VA).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLT_AMPERE_REACTIVE'>
        <xs:annotation>
          <xs:documentation>
            reactive power in an AC electrical circuit (commonly referred to as
            VAR).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLUME_FLUID'>
        <xs:annotation>
          <xs:documentation>
            fluid volume of an object or container.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLUME_SPATIAL'>
        <xs:annotation>
          <xs:documentation>
            geometric volume of an object or container.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WATTAGE'>
        <xs:annotation>
          <xs:documentation>
            power flowing through or dissipated by an electrical circuit or
            piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AMPERAGE_AC'>
        <xs:annotation>
          <xs:documentation>
            electrical current that reverses direction at regular short
            intervals.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AMPERAGE_DC'>
        <xs:annotation>
          <xs:documentation>
            electric current flowing in one direction only.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLTAGE_AC'>
        <xs:annotation>
          <xs:documentation>
            electrical potential between two points in an electrical circuit in
            which the current periodically reverses direction.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLTAGE_DC'>
        <xs:annotation>
          <xs:documentation>
            electrical potential between two points in an electrical circuit in
            which the current is unidirectional.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='X_DIMENSION'>
        <xs:annotation>
          <xs:documentation>
            dimension of an entity relative to the X direction of the referenced
            coordinate system. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='Y_DIMENSION'>
        <xs:annotation>
          <xs:documentation>
            dimension of an entity relative to the Y direction of the referenced
            coordinate system.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='Z_DIMENSION'>
        <xs:annotation>
          <xs:documentation>
            dimension of an entity relative to the Z direction of the referenced
            coordinate system.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DIAMETER'>
        <xs:annotation>
          <xs:documentation>
            dimension of a diameter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ORIENTATION'>
        <xs:annotation>
          <xs:documentation>
            angular position of a plane or vector relative to a {{term(cartesian
            coordinate system)}}
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HUMIDITY_RELATIVE'>
        <xs:annotation>
          <xs:documentation>
            amount of water vapor present expressed as a percent to reach
            saturation at the same temperature.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HUMIDITY_ABSOLUTE'>
        <xs:annotation>
          <xs:documentation>
            amount of water vapor expressed in grams per cubic meter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HUMIDITY_SPECIFIC'>
        <xs:annotation>
          <xs:documentation>
            ratio of the water vapor present over the total weight of the water
            vapor and air present expressed as a percent.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OBSERVATION_UPDATE_RATE'>
        <xs:annotation>
          <xs:documentation>
            average rate of change of values for data items in the MTConnect
            streams. The average is computed over a rolling window defined by
            the implementation.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ASSET_UPDATE_RATE'>
        <xs:annotation>
          <xs:documentation>
            average rate of change of values for assets in the MTConnect
            streams. The average is computed over a rolling window defined by
            the implementation.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PRESSURIZATION_RATE'>
        <xs:annotation>
          <xs:documentation>
            change of pressure per unit time.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DECELERATION'>
        <xs:annotation>
          <xs:documentation>
            negative rate of change of velocity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ANGULAR_DECELERATION'>
        <xs:annotation>
          <xs:documentation>
            negative rate of change of angular velocity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PRESSURE_ABSOLUTE'>
        <xs:annotation>
          <xs:documentation>
            force per unit area measured relative to a vacuum.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPENNESS'>
        <xs:annotation>
          <xs:documentation>
            percentage open where 100% is fully open and 0% is fully closed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEW_POINT'>
        <xs:annotation>
          <xs:documentation>
            temperature at which moisture begins to condense, corresponding to
            saturation for a given absolute humidity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GRAVITATIONAL_FORCE'>
        <xs:annotation>
          <xs:documentation>
            force relative to earth&apos;s gravity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GRAVITATIONAL_ACCELERATION'>
        <xs:annotation>
          <xs:documentation>
            acceleration relative to Earth&apos;s gravity of 9.80665
            `METER/SECOND^2`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BATTERY_CAPACITY'>
        <xs:annotation>
          <xs:documentation>
            maximum rated charge a battery is capable of maintaining based on
            the battery discharging at a specified current over a specified time
            period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DISCHARGE_RATE'>
        <xs:annotation>
          <xs:documentation>
            value of current being drawn from the {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CHARGE_RATE'>
        <xs:annotation>
          <xs:documentation>
            value of the current being supplied to the {{block(Component)}} for
            the purpose of charging.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BATTERY_CHARGE'>
        <xs:annotation>
          <xs:documentation>
            value of the battery&apos;s present capacity expressed as a
            percentage of the battery&apos;s maximum rated capacity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SETTLING_ERROR'>
        <xs:annotation>
          <xs:documentation>
            difference between actual and commanded position at the end of a
            motion.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FOLLOWING_ERROR'>
        <xs:annotation>
          <xs:documentation>
            difference between actual and commanded position at any specific
            point in time during a motion.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SETTLING_ERROR_LINEAR'>
        <xs:annotation>
          <xs:documentation>
            difference between the commanded encoder/resolver position, and the
            actual encoder/resolver position when motion is complete.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SETTLING_ERROR_ANGULAR'>
        <xs:annotation>
          <xs:documentation>
            angular difference between the commanded encoder/resolver position,
            and the actual encoder/resolver position when motion is complete.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FOLLOWING_ERROR_LINEAR'>
        <xs:annotation>
          <xs:documentation>
            difference between the commanded encoder/resolver position and the
            actual encoder/resolver position at any specified point in time
            during a motion.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FOLLOWING_ERROR_ANGULAR'>
        <xs:annotation>
          <xs:documentation>
            angular difference between the commanded encoder/resolver position
            and the actual encoder/resolver position at any specified point in
            time during a motion.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DISPLACEMENT_LINEAR'>
        <xs:annotation>
          <xs:documentation>
            absolute value of the change in position along a vector.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DISPLACEMENT_ANGULAR'>
        <xs:annotation>
          <xs:documentation>
            absolute value of the change in angular position around a vector
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='POSITION_CARTESIAN'>
        <xs:annotation>
          <xs:documentation>
            point in a {{term(cartesian coordinate system)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACTIVE_AXES'>
        <xs:annotation>
          <xs:documentation>
            set of axes currently associated with a {{block(Path)}} or
            {{block(Controller)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACTUATOR_STATE'>
        <xs:annotation>
          <xs:documentation>
            operational state of an apparatus for moving or controlling a
            mechanism or system.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ALARM'>
        <xs:annotation>
          <xs:documentation>
            **DEPRECATED:** Replaced with `CONDITION` category data items in
            Version 1.1.0.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ASSET_CHANGED'>
        <xs:annotation>
          <xs:documentation>
            {{block(assetId)}} of the {{term(Asset)}} that has been added or
            changed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ASSET_REMOVED'>
        <xs:annotation>
          <xs:documentation>
            {{block(assetId)}} of the {{term(Asset)}} that has been removed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AVAILABILITY'>
        <xs:annotation>
          <xs:documentation>
            {{term(agent)}}&apos;s ability to communicate with the data source.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AXIS_COUPLING'>
        <xs:annotation>
          <xs:documentation>
            describes the way the axes will be associated to each other. This is
            used in conjunction with `COUPLED_AXES` to indicate the way they are
            interacting.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AXIS_FEEDRATE_OVERRIDE'>
        <xs:annotation>
          <xs:documentation>
            value of a signal or calculation issued to adjust the feedrate of an
            individual linear type axis.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AXIS_INTERLOCK'>
        <xs:annotation>
          <xs:documentation>
            state of the axis lockout function when power has been removed and
            the axis is allowed to move freely.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AXIS_STATE'>
        <xs:annotation>
          <xs:documentation>
            state of a {{block(Linear)}} or {{block(Rotary)}} component
            representing an axis.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BLOCK'>
        <xs:annotation>
          <xs:documentation>
            line of code or command being executed by a {{block(Controller)}}
            entity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BLOCK_COUNT'>
        <xs:annotation>
          <xs:documentation>
            total count of the number of blocks of program code that have been
            executed since execution started.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CHUCK_INTERLOCK'>
        <xs:annotation>
          <xs:documentation>
            state of an interlock function or control logic state intended to
            prevent the associated {{block(Chuck)}} component from being
            operated.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CHUCK_STATE'>
        <xs:annotation>
          <xs:documentation>
            operating state of a mechanism that holds a part or stock material
            during a manufacturing process. It may also represent a mechanism
            that holds any other mechanism in place within a piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CODE'>
        <xs:annotation>
          <xs:documentation>
            programmatic code being executed. **DEPRECATED** in *Version 1.1*.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COMPOSITION_STATE'>
        <xs:annotation>
          <xs:documentation>
            operating state of a mechanism represented by a
            {{block(Composition)}} entity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CONTROLLER_MODE'>
        <xs:annotation>
          <xs:documentation>
            current mode of the {{block(Controller)}} component.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CONTROLLER_MODE_OVERRIDE'>
        <xs:annotation>
          <xs:documentation>
            setting or operator selection that changes the behavior of a piece
            of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COUPLED_AXES'>
        <xs:annotation>
          <xs:documentation>
            set of associated axes.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DATE_CODE'>
        <xs:annotation>
          <xs:documentation>
            time and date code associated with a material or other physical
            item.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEVICE_UUID'>
        <xs:annotation>
          <xs:documentation>
            identifier of another piece of equipment that is temporarily
            associated with a component of this piece of equipment to perform a
            particular function.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DIRECTION'>
        <xs:annotation>
          <xs:documentation>
            direction of motion.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DOOR_STATE'>
        <xs:annotation>
          <xs:documentation>
            operational state of a {{block(Door)}} component or composition
            element.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='EMERGENCY_STOP'>
        <xs:annotation>
          <xs:documentation>
            state of the emergency stop signal for a piece of equipment,
            controller path, or any other component or subsystem of a piece of
            equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='END_OF_BAR'>
        <xs:annotation>
          <xs:documentation>
            indication of whether the end of a piece of bar stock being feed by
            a bar feeder has been reached.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='EQUIPMENT_MODE'>
        <xs:annotation>
          <xs:documentation>
            indication that a piece of equipment, or a sub-part of a piece of
            equipment, is performing specific types of activities.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='EXECUTION'>
        <xs:annotation>
          <xs:documentation>
            operating state of a {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FUNCTIONAL_MODE'>
        <xs:annotation>
          <xs:documentation>
            current intended production status of the {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HARDNESS'>
        <xs:annotation>
          <xs:documentation>
            hardness of a material.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LINE'>
        <xs:annotation>
          <xs:documentation>
            current line of code being executed. **DEPRECATED** in *Version
            1.4.0*.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LINE_LABEL'>
        <xs:annotation>
          <xs:documentation>
            identifier for a {{block(Block)}} of code in a {{block(Program)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LINE_NUMBER'>
        <xs:annotation>
          <xs:documentation>
            position of a block of program code within a control program.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MATERIAL'>
        <xs:annotation>
          <xs:documentation>
            identifier of a material used or consumed in the manufacturing
            process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MATERIAL_LAYER'>
        <xs:annotation>
          <xs:documentation>
            identifies the layers of material applied to a part or product as
            part of an additive manufacturing process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MESSAGE'>
        <xs:annotation>
          <xs:documentation>
            information to be transferred from a piece of equipment to a client
            software application.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPERATOR_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier of the person currently responsible for operating the
            piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PALLET_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier for a pallet.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_COUNT'>
        <xs:annotation>
          <xs:documentation>
            aggregate count of parts.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_DETECT'>
        <xs:annotation>
          <xs:documentation>
            indication designating whether a part or work piece has been
            detected or is present.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier of a part in a manufacturing operation.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_NUMBER'>
        <xs:annotation>
          <xs:documentation>
            identifier of a part or product moving through the manufacturing
            process. **DEPRECATED** in *Version 1.7*. `PART_NUMBER` is now a
            `subType` of `PART_KIND_ID`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PATH_FEEDRATE_OVERRIDE'>
        <xs:annotation>
          <xs:documentation>
            value of a signal or calculation issued to adjust the feedrate for
            the axes associated with a {{block(Path)}} component that may
            represent a single axis or the coordinated movement of multiple
            axes.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PATH_MODE'>
        <xs:annotation>
          <xs:documentation>
            describes the operational relationship between a {{block(Path)}}
            entity and another {{block(Path)}} entity for pieces of equipment
            comprised of multiple logical groupings of controlled axes or other
            logical operations.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='POWER_STATE'>
        <xs:annotation>
          <xs:documentation>
            indication of the status of the source of energy for an entity to
            allow it to perform its intended function or the state of an
            enabling signal providing permission for the entity to perform its
            functions.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='POWER_STATUS'>
        <xs:annotation>
          <xs:documentation>
            status of the {{block(Component)}}. **DEPRECATED** in *Version
            1.1.0*.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS_TIME'>
        <xs:annotation>
          <xs:documentation>
            time and date associated with an activity or event.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROGRAM'>
        <xs:annotation>
          <xs:documentation>
            name of the logic or motion program being executed by the
            {{block(Controller)}} component.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROGRAM_COMMENT'>
        <xs:annotation>
          <xs:documentation>
            comment or non-executable statement in the control program.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROGRAM_EDIT'>
        <xs:annotation>
          <xs:documentation>
            indication of the status of the {{block(Controller)}} components
            program editing mode. A program may be edited while another is
            executed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROGRAM_EDIT_NAME'>
        <xs:annotation>
          <xs:documentation>
            name of the program being edited. This is used in conjunction with
            {{block(ProgramEdit)}} when in `ACTIVE` state. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROGRAM_HEADER'>
        <xs:annotation>
          <xs:documentation>
            non-executable header section of the control program.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROGRAM_LOCATION'>
        <xs:annotation>
          <xs:documentation>
            {{term(URI)}} for the source file associated with
            {{block(Program)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROGRAM_LOCATION_TYPE'>
        <xs:annotation>
          <xs:documentation>
            defines whether the logic or motion program defined by
            {{block(Program)}} is being executed from the local memory of the
            controller or from an outside source.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROGRAM_NEST_LEVEL'>
        <xs:annotation>
          <xs:documentation>
            indication of the nesting level within a control program that is
            associated with the code or instructions that is currently being
            executed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ROTARY_MODE'>
        <xs:annotation>
          <xs:documentation>
            current operating mode for a {{block(Rotary)}} type axis.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ROTARY_VELOCITY_OVERRIDE'>
        <xs:annotation>
          <xs:documentation>
            percentage change to the velocity of the programmed velocity for a
            {{block(Rotary)}} axis.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SERIAL_NUMBER'>
        <xs:annotation>
          <xs:documentation>
            serial number associated with a {{block(Component)}},
            {{block(Asset)}}, or {{block(Device)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SPINDLE_INTERLOCK'>
        <xs:annotation>
          <xs:documentation>
            indication of the status of the spindle for a piece of equipment
            when power has been removed and it is free to rotate.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TOOL_ASSET_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier of an individual tool asset.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TOOL_GROUP'>
        <xs:annotation>
          <xs:documentation>
            identifier for the tool group associated with a specific tool.
            Commonly used to designate spare tools.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TOOL_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier of the tool currently in use for a given `Path`.
            **DEPRECATED** in *Version 1.2.0*. See `TOOL_ASSET_ID`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TOOL_NUMBER'>
        <xs:annotation>
          <xs:documentation>
            identifier assigned by the {{block(Controller)}} component to a
            cutting tool when in use by a piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TOOL_OFFSET'>
        <xs:annotation>
          <xs:documentation>
            reference to the tool offset variables applied to the active cutting
            tool.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='USER'>
        <xs:annotation>
          <xs:documentation>
            identifier of the person currently responsible for operating the
            piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VARIABLE'>
        <xs:annotation>
          <xs:documentation>
            data whose meaning may change over time due to changes in the
            operation of a piece of equipment or the process being executed on
            that piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WAIT_STATE'>
        <xs:annotation>
          <xs:documentation>
            indication of the reason that {{block(Execution)}} is reporting a
            value of `WAIT`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WIRE'>
        <xs:annotation>
          <xs:documentation>
            identifier for the type of wire used as the cutting mechanism in
            Electrical Discharge Machining or similar processes.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WORKHOLDING_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier for the current workholding or part clamp in use by a
            piece of equipment. **DEPRECATION WARNING**: Recommend using
            `FIXTURE_ID` instead.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WORK_OFFSET'>
        <xs:annotation>
          <xs:documentation>
            reference to offset variables for a work piece or part.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPERATING_SYSTEM'>
        <xs:annotation>
          <xs:documentation>
            Operating System (OS) of a {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FIRMWARE'>
        <xs:annotation>
          <xs:documentation>
            embedded software of a {{block(Component)}} .
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='APPLICATION'>
        <xs:annotation>
          <xs:documentation>
            application on a {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LIBRARY'>
        <xs:annotation>
          <xs:documentation>
            software library on a {{block(Component)}}
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HARDWARE'>
        <xs:annotation>
          <xs:documentation>
            hardware of a {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='NETWORK'>
        <xs:annotation>
          <xs:documentation>
            network details of a {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ROTATION'>
        <xs:annotation>
          <xs:documentation>
            three space angular displacement of an object or coordinate system
            relative to a {{term(cartesian coordinate system)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TRANSLATION'>
        <xs:annotation>
          <xs:documentation>
            three space linear displacement of an object or coordinate system
            relative to a {{term(cartesian coordinate system)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEVICE_ADDED'>
        <xs:annotation>
          <xs:documentation>
            {{term(UUID)}} of new device added to an {{term(MTConnect Agent)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEVICE_REMOVED'>
        <xs:annotation>
          <xs:documentation>
            {{term(UUID)}} of a device removed from an {{term(MTConnect
            Agent)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEVICE_CHANGED'>
        <xs:annotation>
          <xs:documentation>
            {{term(UUID)}} of the device whose {{term(metadata)}} has changed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CONNECTION_STATUS'>
        <xs:annotation>
          <xs:documentation>
            status of the connection between an {{term(adapter)}} and an
            {{term(agent)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ADAPTER_SOFTWARE_VERSION'>
        <xs:annotation>
          <xs:documentation>
            originator’s software version of the {{term(adapter)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ADAPTER_URI'>
        <xs:annotation>
          <xs:documentation>
            {{term(URI)}} of the {{term(adapter)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MTCONNECT_VERSION'>
        <xs:annotation>
          <xs:documentation>
            reference version of the MTConnect Standard supported by the
            {{term(adapter)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SENSOR_ATTACHMENT'>
        <xs:annotation>
          <xs:documentation>
            {{term(attachment)}} between a sensor and an entity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_STATUS'>
        <xs:annotation>
          <xs:documentation>
            state or condition of a part.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS_OCCURRENCE_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier of a process being executed by the device.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS_AGGREGATE_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier given to link the individual occurrence to a group of
            related occurrences, such as a process step in a process plan.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS_KIND_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier given to link the individual occurrence to a class of
            processes or process definition. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_GROUP_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier given to a collection of individual parts. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_KIND_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier given to link the individual occurrence to a class of
            parts, typically distinguished by a particular part design.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_UNIQUE_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier given to a distinguishable, individual part. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CONTROL_LIMIT'>
        <xs:annotation>
          <xs:documentation>
            set of limits used to indicate whether a process variable is stable
            and in control. **DEPRECATION WARNING**. Recommend using
            `CONTROL_LIMITS`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SPECIFICATION_LIMIT'>
        <xs:annotation>
          <xs:documentation>
            set of limits defining a range of values designating acceptable
            performance for a variable. **DEPRECATION WARNING**. Recommend using
            `SPECIFICATION_LIMITS`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ALARM_LIMIT'>
        <xs:annotation>
          <xs:documentation>
            set of limits used to trigger warning or alarm indicators.
            **DEPRECATION WARNING**. Recommend using `ALARM_LIMITS`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LOAD_COUNT'>
        <xs:annotation>
          <xs:documentation>
            accumulation of the number of times an operation has attempted to,
            or is planned to attempt to, load materials, parts, or other items.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='UNLOAD_COUNT'>
        <xs:annotation>
          <xs:documentation>
            accumulation of the number of times an operation has attempted to,
            or is planned to attempt to, unload materials, parts, or other
            items.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TRANSFER_COUNT'>
        <xs:annotation>
          <xs:documentation>
            accumulation of the number of times an operation has attempted to,
            or is planned to attempt to, transfer materials, parts, or other
            items from one location to another.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACTIVATION_COUNT'>
        <xs:annotation>
          <xs:documentation>
            accumulation of the number of times a function has attempted to, or
            is planned to attempt to, activate or be performed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEACTIVATION_COUNT'>
        <xs:annotation>
          <xs:documentation>
            accumulation of the number of times a function has attempted to, or
            is planned to attempt to, deactivate or cease.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CYCLE_COUNT'>
        <xs:annotation>
          <xs:documentation>
            accumulation of the number of times a cyclic function has attempted
            to, or is planned to attempt to execute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VALVE_STATE'>
        <xs:annotation>
          <xs:documentation>
            state of a valve is one of open, closed, or transitioning between
            the states.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LOCK_STATE'>
        <xs:annotation>
          <xs:documentation>
            state or operating mode of a {{block(Lock)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS_STATE'>
        <xs:annotation>
          <xs:documentation>
            particular condition of the process occurrence at a specific time.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_PROCESSING_STATE'>
        <xs:annotation>
          <xs:documentation>
            particular condition of the part occurrence at a specific time.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPERATING_MODE'>
        <xs:annotation>
          <xs:documentation>
            state of {{block(Component)}} or {{block(Composition)}} that
            describes the automatic or manual operation of the entity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ASSET_COUNT'>
        <xs:annotation>
          <xs:documentation>
            {{term(data set)}} of the number of {{termplural(Asset)}} of a given
            type for a {{term(Device)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MAINTENANCE_LIST'>
        <xs:annotation>
          <xs:documentation>
            actions or activities to be performed in support of a piece of
            equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FIXTURE_ID'>
        <xs:annotation>
          <xs:documentation>
            identifier for the current workholding or part clamp in use by a
            piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_COUNT_TYPE'>
        <xs:annotation>
          <xs:documentation>
            interpretation of `PART_COUNT`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CLOCK_TIME'>
        <xs:annotation>
          <xs:documentation>
            time provided by a timing device at a specific point in time.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HOST_NAME'>
        <xs:annotation>
          <xs:documentation>
            name of the host computer supplying data.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='NETWORK_PORT'>
        <xs:annotation>
          <xs:documentation>
            number of the TCP/IP or UDP/IP port for the connection endpoint.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LEAK_DETECT'>
        <xs:annotation>
          <xs:documentation>
            indication designating whether a leak has been detected.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BATTERY_STATE'>
        <xs:annotation>
          <xs:documentation>
            present status of the battery.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FEATURE_PERSISTENT_ID'>
        <xs:annotation>
          <xs:documentation>
            {{term(UUID)}} of a {{term(feature)}}. {{cite(ISO 10303 AP
            242/239)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SENSOR_STATE'>
        <xs:annotation>
          <xs:documentation>
            detection result of a sensor.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COMPONENT_DATA'>
        <xs:annotation>
          <xs:documentation>
            {{block(Event)}} that represents a {{block(Component)}} where the
            {{block(EntryDefinition)}} identifies the {{block(Component)}} and
            the {{block(CellDefinition)}}s define the
            {{block(Component)}}&apos;s observed {{block(DataItem)}}s.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WORK_OFFSETS'>
        <xs:annotation>
          <xs:documentation>
            properties of each addressable work offset.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TOOL_OFFSETS'>
        <xs:annotation>
          <xs:documentation>
            properties of each addressable tool offset.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FEATURE_MEASUREMENT'>
        <xs:annotation>
          <xs:documentation>
            assessing elements of a {{term(feature)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CHARACTERISTIC_PERSISTENT_ID'>
        <xs:annotation>
          <xs:documentation>
            {{term(UUID)}} of the {{term(characteristic)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MEASUREMENT_TYPE'>
        <xs:annotation>
          <xs:documentation>
            class of measurement being performed. {{cite(QIF 3:2018 Section
            6.3)}}
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MEASUREMENT_VALUE'>
        <xs:annotation>
          <xs:documentation>
            measurement based on the measurement type.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MEASUREMENT_UNITS'>
        <xs:annotation>
          <xs:documentation>
            engineering units of the measurement.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CHARACTERISTIC_STATUS'>
        <xs:annotation>
          <xs:documentation>
            pass/fail result of the measurement.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='UNCERTAINTY_TYPE'>
        <xs:annotation>
          <xs:documentation>
            method used to compute {{term(standard uncertainty)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='UNCERTAINTY'>
        <xs:annotation>
          <xs:documentation>
            {{term(uncertainty)}} specified by {{block(UncertaintyType)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SPECIFICATION_LIMITS'>
        <xs:annotation>
          <xs:documentation>
            set of limits defining a range of values designating acceptable
            performance for a variable.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CONTROL_LIMITS'>
        <xs:annotation>
          <xs:documentation>
            set of limits used to indicate whether a process variable is stable
            and in control.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ALARM_LIMITS'>
        <xs:annotation>
          <xs:documentation>
            set of limits used to trigger warning or alarm indicators.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TOOL_CUTTING_ITEM'>
        <xs:annotation>
          <xs:documentation>
            references the {{block(CuttingToolLifeCycle)}}
            {{block(CuttingItem)}} index related to the
            {{property(CuttingItem::indices)}} of the currently active cutting
            tool edge.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LOCATION_ADDRESS'>
        <xs:annotation>
          <xs:documentation>
            structured information that allows the unambiguous determination of
            an object for purposes of identification and location. {{cite(ISO
            19160-4:2017)}}
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACTIVE_POWER_SOURCE'>
        <xs:annotation>
          <xs:documentation>
            active energy source for the {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COMMUNICATIONS'>
        <xs:annotation>
          <xs:documentation>
            indication that the piece of equipment has experienced a
            communications failure.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DATA_RANGE'>
        <xs:annotation>
          <xs:documentation>
            indication that the value of the data associated with a measured
            value or a calculation is outside of an expected range.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LOGIC_PROGRAM'>
        <xs:annotation>
          <xs:documentation>
            indication that an error occurred in the logic program or
            programmable logic controller (PLC) associated with a piece of
            equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MOTION_PROGRAM'>
        <xs:annotation>
          <xs:documentation>
            indication that an error occurred in the motion program associated
            with a piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SYSTEM'>
        <xs:annotation>
          <xs:documentation>
            general purpose indication associated with an electronic component
            of a piece of equipment or a controller that represents a fault that
            is not associated with the operator, program, or hardware.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACTUATOR'>
        <xs:annotation>
          <xs:documentation>
            indication of a fault associated with an actuator.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INTERFACE_STATE'>
        <xs:annotation>
          <xs:documentation>
            operational state of an {{block(Interface)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MATERIAL_FEED'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to advance material or feed product
            to a piece of equipment from a continuous or bulk source.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MATERIAL_CHANGE'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to change the type of material or
            product being loaded or fed to a piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MATERIAL_RETRACT'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to remove or retract material or
            product.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_CHANGE'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to change the part or product
            associated with a piece of equipment to a different part or product.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MATERIAL_LOAD'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to load a piece of material or
            product.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MATERIAL_UNLOAD'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to unload a piece of material or
            product.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPEN_CHUCK'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to open a chuck.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPEN_DOOR'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to open a door.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CLOSE_CHUCK'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to close a chuck.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CLOSE_DOOR'>
        <xs:annotation>
          <xs:documentation>
            operating state of the service to close a door.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VARIABLE'>
        <xs:annotation>
          <xs:documentation>
            A user variable
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DataItemEnumType'>
    <xs:annotation>
      <xs:documentation>
        The types of measurements available
      </xs:documentation>
    </xs:annotation>
    <xs:union memberTypes='DataItemEnumEnum DataItemEnumExtType'/>
  </xs:simpleType>
  <xs:simpleType name='DataItemSubEnumExtType'>
    <xs:annotation>
      <xs:documentation>
        Extended tyoe for The sub-types for a measurement
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:pattern value='[a-ln-z][a-z]*:[A-Z_0-9]+'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DataItemSubEnumEnum'>
    <xs:annotation>
      <xs:documentation>
        The sub-types for a measurement
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:enumeration value='ABSOLUTE'>
        <xs:annotation>
          <xs:documentation>
            relating to or derived in the simplest manner from the fundamental
            units or measurements.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACTION'>
        <xs:annotation>
          <xs:documentation>
            indication of the operating state of a mechanism.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACTUAL'>
        <xs:annotation>
          <xs:documentation>
            measured or reported value of an {{term(observation)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ALL'>
        <xs:annotation>
          <xs:documentation>
            all actions, items, or activities being counted independent of the
            outcome.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ALTERNATING'>
        <xs:annotation>
          <xs:documentation>
            measurement of alternating voltage or current. If not specified
            further in statistic, defaults to RMS voltage. **DEPRECATED** in
            *Version 1.6*.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='A_SCALE'>
        <xs:annotation>
          <xs:documentation>
            A-Scale weighting factor on the frequency scale.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AUXILIARY'>
        <xs:annotation>
          <xs:documentation>
            when multiple locations on a piece of bar stock being feed by a bar
            feeder are referenced as the indication of whether the end of that
            piece of bar stock has been reached.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BAD'>
        <xs:annotation>
          <xs:documentation>
            actions, items, or activities being counted that do not conform to
            specification or expectation.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BRINELL'>
        <xs:annotation>
          <xs:documentation>
            scale to measure the resistance to deformation of a surface.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='B_SCALE'>
        <xs:annotation>
          <xs:documentation>
            B-Scale weighting factor on the frequency scale.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COMMANDED'>
        <xs:annotation>
          <xs:documentation>
            directive value including adjustments such as an offset or
            overrides.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CONSUMED'>
        <xs:annotation>
          <xs:documentation>
            amount of material consumed from an object or container during a
            manufacturing process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CONTROL'>
        <xs:annotation>
          <xs:documentation>
            state of the enabling signal or control logic that enables or
            disables the function or operation of the entity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='C_SCALE'>
        <xs:annotation>
          <xs:documentation>
            C-Scale weighting factor on the frequency scale.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DELAY'>
        <xs:annotation>
          <xs:documentation>
            elapsed time of a temporary halt of action.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DIRECT'>
        <xs:annotation>
          <xs:documentation>
            DC current or voltage. **DEPRECATED** in *Version 1.6*.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DRY_RUN'>
        <xs:annotation>
          <xs:documentation>
            setting or operator selection used to execute a test mode to confirm
            the execution of machine functions.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='D_SCALE'>
        <xs:annotation>
          <xs:documentation>
            D-Scale weighting factor on the frequency scale.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='EXPIRATION'>
        <xs:annotation>
          <xs:documentation>
            relating to the expiration or end of useful life for a material or
            other physical item.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FIRST_USE'>
        <xs:annotation>
          <xs:documentation>
            relating to the first use of a material or other physical item.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GOOD'>
        <xs:annotation>
          <xs:documentation>
            actions, items, or activities being counted that conform to
            specification or expectation.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INCREMENTAL'>
        <xs:annotation>
          <xs:documentation>
            relating to or derived from the last {{term(observation)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='JOG'>
        <xs:annotation>
          <xs:documentation>
            relating to momentary activation of a function or a movement.
            **DEPRECATION WARNING**: May be deprecated in the future.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LATERAL'>
        <xs:annotation>
          <xs:documentation>
            indication of the position of a mechanism that may move in a lateral
            direction.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LEEB'>
        <xs:annotation>
          <xs:documentation>
            scale to measure the elasticity of a surface.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LENGTH'>
        <xs:annotation>
          <xs:documentation>
            reference to a length type tool offset variable.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LINE'>
        <xs:annotation>
          <xs:documentation>
            state of the power source.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LINEAR'>
        <xs:annotation>
          <xs:documentation>
            direction of motion of a linear motion.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LOADED'>
        <xs:annotation>
          <xs:documentation>
            indication that the subparts of a piece of equipment are under load.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MACHINE_AXIS_LOCK'>
        <xs:annotation>
          <xs:documentation>
            setting or operator selection that changes the behavior of the
            controller on a piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MAIN'>
        <xs:annotation>
          <xs:documentation>
            relating to the primary logic or motion program currently being
            executed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MAINTENANCE'>
        <xs:annotation>
          <xs:documentation>
            relating to maintenance on the piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MANUAL_UNCLAMP'>
        <xs:annotation>
          <xs:documentation>
            indication of the state of an operator controlled interlock that can
            inhibit the ability to initiate an unclamp action of an
            electronically controlled chuck.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MANUFACTURE'>
        <xs:annotation>
          <xs:documentation>
            related to the production of a material or other physical item.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MAXIMUM'>
        <xs:annotation>
          <xs:documentation>
            maximum value.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MINIMUM'>
        <xs:annotation>
          <xs:documentation>
            minimum value.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MOHS'>
        <xs:annotation>
          <xs:documentation>
            scale to measure the resistance to scratching of a surface.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MOTION'>
        <xs:annotation>
          <xs:documentation>
            indication of the open or closed state of a mechanism.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='NO_SCALE'>
        <xs:annotation>
          <xs:documentation>
            no weighting factor on the frequency scale.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPERATING'>
        <xs:annotation>
          <xs:documentation>
            piece of equipment that is powered or performing any activity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPERATOR'>
        <xs:annotation>
          <xs:documentation>
            relating to the person currently responsible for operating the piece
            of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPTIONAL_STOP'>
        <xs:annotation>
          <xs:documentation>
            setting or operator selection that changes the behavior of the
            controller on a piece of equipment. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OVERRIDE'>
        <xs:annotation>
          <xs:documentation>
            overridden value.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='POWERED'>
        <xs:annotation>
          <xs:documentation>
            piece of equipment is powered and functioning or
            {{block(Component)}} that are required to remain on are powered.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PRIMARY'>
        <xs:annotation>
          <xs:documentation>
            main or principle.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROBE'>
        <xs:annotation>
          <xs:documentation>
            position provided by a measurement probe. **DEPRECATION WARNING**:
            May be deprecated in the future.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS'>
        <xs:annotation>
          <xs:documentation>
            relating to production of a part or product on a piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROGRAMMED'>
        <xs:annotation>
          <xs:documentation>
            directive value without offsets and adjustments.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RADIAL'>
        <xs:annotation>
          <xs:documentation>
            reference to a radial type tool offset variable.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RAPID'>
        <xs:annotation>
          <xs:documentation>
            performing an operation faster or in less time than nominal rate.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='REMAINING'>
        <xs:annotation>
          <xs:documentation>
            remaining measure or count of an action, object or activity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ROCKWELL'>
        <xs:annotation>
          <xs:documentation>
            scale to measure the resistance to deformation of a surface.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ROTARY'>
        <xs:annotation>
          <xs:documentation>
            direction of a rotary motion using the right hand rule convention.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SCHEDULE'>
        <xs:annotation>
          <xs:documentation>
            identity of a control program that is used to specify the order of
            execution of other programs.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SET_UP'>
        <xs:annotation>
          <xs:documentation>
            relating to the preparation of a piece of equipment for production
            or restoring the piece of equipment to a neutral state after
            production.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SHORE'>
        <xs:annotation>
          <xs:documentation>
            scale to measure the resistance to deformation of a surface.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SINGLE_BLOCK'>
        <xs:annotation>
          <xs:documentation>
            setting or operator selection that changes the behavior of the
            controller on a piece of equipment. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='STANDARD'>
        <xs:annotation>
          <xs:documentation>
            standard measure of an object or an action.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='START'>
        <xs:annotation>
          <xs:documentation>
            boundary when an activity or an event commences.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SWITCHED'>
        <xs:annotation>
          <xs:documentation>
            indication of the activation state of a mechanism represented by a
            {{block(Composition)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TARGET'>
        <xs:annotation>
          <xs:documentation>
            goal of the operation or process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TARGET_COMPLETION'>
        <xs:annotation>
          <xs:documentation>
            relating to the end or completion of an activity or event.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TOOL_CHANGE_STOP'>
        <xs:annotation>
          <xs:documentation>
            setting or operator selection that changes the behavior of the
            controller on a piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='USEABLE'>
        <xs:annotation>
          <xs:documentation>
            remaining usable measure of an object or action.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VERTICAL'>
        <xs:annotation>
          <xs:documentation>
            indication of the position of a mechanism that may move in a
            vertical direction.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VICKERS'>
        <xs:annotation>
          <xs:documentation>
            scale to measure the resistance to deformation of a surface.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WORKING'>
        <xs:annotation>
          <xs:documentation>
            piece of equipment performing any activity, the equipment is active
            and performing a function under load or not.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='IPV4_ADDRESS'>
        <xs:annotation>
          <xs:documentation>
            IPV4 network address of the {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='IPV6_ADDRESS'>
        <xs:annotation>
          <xs:documentation>
            IPV6 network address of the {{block(Component)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GATEWAY'>
        <xs:annotation>
          <xs:documentation>
            Gateway for the {{block(Component)}} network.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SUBNET_MASK'>
        <xs:annotation>
          <xs:documentation>
            SubNet mask for the {{block(Component)}} network. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VLAN_ID'>
        <xs:annotation>
          <xs:documentation>
            layer2 Virtual Local Network (VLAN) ID for the {{block(Component)}}
            network.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MAC_ADDRESS'>
        <xs:annotation>
          <xs:documentation>
            Media Access Control Address. The unique physical address of the
            network hardware.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WIRELESS'>
        <xs:annotation>
          <xs:documentation>
            identifies whether the connection type is wireless.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LICENSE'>
        <xs:annotation>
          <xs:documentation>
            license code to validate or activate the hardware or software.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VERSION'>
        <xs:annotation>
          <xs:documentation>
            version of the hardware or software. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RELEASE_DATE'>
        <xs:annotation>
          <xs:documentation>
            date the hardware or software was released for general use.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INSTALL_DATE'>
        <xs:annotation>
          <xs:documentation>
            date the hardware or software was installed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MANUFACTURER'>
        <xs:annotation>
          <xs:documentation>
            corporate identity for the maker of the hardware or software.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='UUID'>
        <xs:annotation>
          <xs:documentation>
            universally unique identifier as specified in ISO 11578 or RFC 4122.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SERIAL_NUMBER'>
        <xs:annotation>
          <xs:documentation>
            serial number that uniquely identifies a specific part.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RAW_MATERIAL'>
        <xs:annotation>
          <xs:documentation>
            material that is used to produce parts.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LOT'>
        <xs:annotation>
          <xs:documentation>
            group of parts tracked as a lot.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BATCH'>
        <xs:annotation>
          <xs:documentation>
            group of parts produced in a batch.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HEAT_TREAT'>
        <xs:annotation>
          <xs:documentation>
            material heat number.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_NUMBER'>
        <xs:annotation>
          <xs:documentation>
            particular part design or model.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_FAMILY'>
        <xs:annotation>
          <xs:documentation>
            group of parts having similarities in geometry, manufacturing
            process, and/or functions.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART_NAME'>
        <xs:annotation>
          <xs:documentation>
            word or set of words by which a part is known, addressed, or
            referred to.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS_STEP'>
        <xs:annotation>
          <xs:documentation>
            step in the process plan that this occurrence corresponds to. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS_PLAN'>
        <xs:annotation>
          <xs:documentation>
            process plan that a process occurrence belongs to.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ORDER_NUMBER'>
        <xs:annotation>
          <xs:documentation>
            authorization of a process occurrence.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PROCESS_NAME'>
        <xs:annotation>
          <xs:documentation>
            word or set of words by which a process being executed (process
            occurrence) by the device is known, addressed, or referred to. 
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ISO_STEP_EXECUTABLE'>
        <xs:annotation>
          <xs:documentation>
            reference to a ISO 10303 Executable.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COMPLETE'>
        <xs:annotation>
          <xs:documentation>
            associated with the completion of an activity or event.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACTIVE'>
        <xs:annotation>
          <xs:documentation>
            relating to logic or motion program currently executing.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FAILED'>
        <xs:annotation>
          <xs:documentation>
            actions or activities that were attempted , but failed to complete
            or resulted in an unexpected or unacceptable outcome.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ABORTED'>
        <xs:annotation>
          <xs:documentation>
            actions or activities that were attempted, but terminated before
            they could be completed.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ENDED'>
        <xs:annotation>
          <xs:documentation>
            boundary when an activity or an event terminates.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WASTE'>
        <xs:annotation>
          <xs:documentation>
            amount discarded.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PART'>
        <xs:annotation>
          <xs:documentation>
            amount included in the {{term(part)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='REQUEST'>
        <xs:annotation>
          <xs:documentation>
            {{term(request)}} by an {{block(Interface)}} for a task.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RESPONSE'>
        <xs:annotation>
          <xs:documentation>
            {{term(response)}} by an {{block(Interface)}} to a {{term(request)}}
            for a task.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ACTIVITY'>
        <xs:annotation>
          <xs:documentation>
            phase or segment of a recipe or program.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SEGMENT'>
        <xs:annotation>
          <xs:documentation>
            phase of a recipe process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RECIPE'>
        <xs:annotation>
          <xs:documentation>
            process as part of product production; can be a subprocess of a
            larger process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OPERATION'>
        <xs:annotation>
          <xs:documentation>
            step of a discrete manufacturing process.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BINARY'>
        <xs:annotation>
          <xs:documentation>
            observed as a binary data type.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BOOLEAN'>
        <xs:annotation>
          <xs:documentation>
            observed as a boolean data type.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ENUMERATED'>
        <xs:annotation>
          <xs:documentation>
            observed as a set containing a restricted number of discrete values
            where each discrete value is named and unique. {{cite(ISO
            21961:2003, 013)}}
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DETECT'>
        <xs:annotation>
          <xs:documentation>
            indicated by the presence or existence of something.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MODEL'>
        <xs:annotation>
          <xs:documentation>
            model info of the hardware or software.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DataItemSubEnumType'>
    <xs:annotation>
      <xs:documentation>
        The sub-types for a measurement
      </xs:documentation>
    </xs:annotation>
    <xs:union memberTypes='DataItemSubEnumEnum DataItemSubEnumExtType'/>
  </xs:simpleType>
  <xs:simpleType name='DataItemStatisticsExtType'>
    <xs:annotation>
      <xs:documentation>
        Extended tyoe for Statistical operations on data
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:pattern value='[a-ln-z][a-z]*:[A-Z_0-9]+'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DataItemStatisticsEnum'>
    <xs:annotation>
      <xs:documentation>
        Statistical operations on data
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:enumeration value='AVERAGE'>
        <xs:annotation>
          <xs:documentation>
            mathematical average value calculated for the data item during the
            calculation period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='KURTOSIS'>
        <xs:annotation>
          <xs:documentation>
            **DEPRECATED** in *Version 1.6*. ~~A measure of the
            &quot;peakedness&quot; of a probability distribution; i.e., the
            shape of the distribution curve.~~
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MAXIMUM'>
        <xs:annotation>
          <xs:documentation>
            maximum or peak value recorded for the data item during the
            calculation period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MEDIAN'>
        <xs:annotation>
          <xs:documentation>
            middle number of a series of numbers.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MINIMUM'>
        <xs:annotation>
          <xs:documentation>
            minimum value recorded for the data item during the calculation
            period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MODE'>
        <xs:annotation>
          <xs:documentation>
            number in a series of numbers that occurs most often.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RANGE'>
        <xs:annotation>
          <xs:documentation>
            difference between the maximum and minimum value of a data item
            during the calculation period. Also represents Peak-to-Peak
            measurement in a waveform.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ROOT_MEAN_SQUARE'>
        <xs:annotation>
          <xs:documentation>
            mathematical Root Mean Square (RMS) value calculated for the data
            item during the calculation period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='STANDARD_DEVIATION'>
        <xs:annotation>
          <xs:documentation>
            statistical Standard Deviation value calculated for the data item
            during the calculation period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DataItemStatisticsType'>
    <xs:annotation>
      <xs:documentation>
        Statistical operations on data
      </xs:documentation>
    </xs:annotation>
    <xs:union memberTypes='DataItemStatisticsEnum DataItemStatisticsExtType'/>
  </xs:simpleType>
  <xs:simpleType name='UnitsExtType'>
    <xs:annotation>
      <xs:documentation>
        Extended tyoe for same as {{property(DataItem::units)}}. See
        {{package(Device Information Model)}}.
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:pattern value='[a-ln-z][a-z]*:[A-Z_0-9]+'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='UnitsEnum'>
    <xs:annotation>
      <xs:documentation>
        same as {{property(DataItem::units)}}. See {{package(Device Information
        Model)}}.
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:enumeration value='AMPERE'>
        <xs:annotation>
          <xs:documentation>
            amps.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CELSIUS'>
        <xs:annotation>
          <xs:documentation>
            degrees Celsius.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COUNT'>
        <xs:annotation>
          <xs:documentation>
            count of something.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DECIBEL'>
        <xs:annotation>
          <xs:documentation>
            sound level.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEGREE'>
        <xs:annotation>
          <xs:documentation>
            angle in degrees.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEGREE_3D'>
        <xs:annotation>
          <xs:documentation>
            space-delimited, floating-point representation of the angular
            rotation in degrees around the X, Y, and Z axes relative to a
            cartesian coordinate system respectively in order as A, B, and C. If
            any of the rotations is not known, it **MUST** be zero (0).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEGREE/SECOND'>
        <xs:annotation>
          <xs:documentation>
            angular degrees per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEGREE/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            angular acceleration in degrees per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HERTZ'>
        <xs:annotation>
          <xs:documentation>
            frequency measured in cycles per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='JOULE'>
        <xs:annotation>
          <xs:documentation>
            measurement of energy.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='KILOGRAM'>
        <xs:annotation>
          <xs:documentation>
            kilograms.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LITER'>
        <xs:annotation>
          <xs:documentation>
            measurement of volume of a fluid.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LITER/SECOND'>
        <xs:annotation>
          <xs:documentation>
            liters per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MICRO_RADIAN'>
        <xs:annotation>
          <xs:documentation>
            measurement of tilt.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER'>
        <xs:annotation>
          <xs:documentation>
            millimeters.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER_3D'>
        <xs:annotation>
          <xs:documentation>
            point in space identified by X, Y, and Z positions and represented
            by a space-delimited set of numbers each expressed in millimeters.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER/REVOLUTION'>
        <xs:annotation>
          <xs:documentation>
            millimeters per revolution.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER/SECOND'>
        <xs:annotation>
          <xs:documentation>
            millimeters per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            acceleration in millimeters per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='NEWTON'>
        <xs:annotation>
          <xs:documentation>
            force in Newtons.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='NEWTON_METER'>
        <xs:annotation>
          <xs:documentation>
            torque, a unit for force times distance.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OHM'>
        <xs:annotation>
          <xs:documentation>
            measure of electrical resistance.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PASCAL'>
        <xs:annotation>
          <xs:documentation>
            pressure in Newtons per square meter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PASCAL_SECOND'>
        <xs:annotation>
          <xs:documentation>
            measurement of viscosity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PERCENT'>
        <xs:annotation>
          <xs:documentation>
            percentage.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PH'>
        <xs:annotation>
          <xs:documentation>
            measure of the acidity or alkalinity of a solution.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='REVOLUTION/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            revolutions per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SECOND'>
        <xs:annotation>
          <xs:documentation>
            measurement of time.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SIEMENS/METER'>
        <xs:annotation>
          <xs:documentation>
            measurement of electrical conductivity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLT'>
        <xs:annotation>
          <xs:documentation>
            volts.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLT_AMPERE'>
        <xs:annotation>
          <xs:documentation>
            measurement of the apparent power in an electrical circuit, equal to
            the product of root-mean-square (RMS) voltage and RMS current
            (commonly referred to as VA).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLT_AMPERE_REACTIVE'>
        <xs:annotation>
          <xs:documentation>
            measurement of reactive power in an AC electrical circuit (commonly
            referred to as VAR).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WATT'>
        <xs:annotation>
          <xs:documentation>
            watts.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WATT_SECOND'>
        <xs:annotation>
          <xs:documentation>
            measurement of electrical energy, equal to one Joule.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GRAM/CUBIC_METER'>
        <xs:annotation>
          <xs:documentation>
            gram per cubic meter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CUBIC_MILLIMETER'>
        <xs:annotation>
          <xs:documentation>
            geometric volume in millimeters.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CUBIC_MILLIMETER/SECOND'>
        <xs:annotation>
          <xs:documentation>
            change of geometric volume per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CUBIC_MILLIMETER/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            change in geometric volume per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIGRAM'>
        <xs:annotation>
          <xs:documentation>
            milligram.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIGRAM/CUBIC_MILLIMETER'>
        <xs:annotation>
          <xs:documentation>
            milligram per cubic millimeter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLILITER'>
        <xs:annotation>
          <xs:documentation>
            milliliter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COUNT/SECOND'>
        <xs:annotation>
          <xs:documentation>
            counts per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PASCAL/SECOND'>
        <xs:annotation>
          <xs:documentation>
            pascal per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='UNIT_VECTOR_3D'>
        <xs:annotation>
          <xs:documentation>
            3D Unit Vector. Space delimited list of three floating point
            numbers.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='REVOLUTION/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            revolutions per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='REVOLUTION/SECOND'>
        <xs:annotation>
          <xs:documentation>
            rotational velocity in revolution per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GRAM'>
        <xs:annotation>
          <xs:documentation>
            gram.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='METER/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            acceleration in meters per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COULOMB'>
        <xs:annotation>
          <xs:documentation>
            electric charge in coulombs (C).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='UnitsType'>
    <xs:annotation>
      <xs:documentation>
        same as {{property(DataItem::units)}}. See {{package(Device Information
        Model)}}.
      </xs:documentation>
    </xs:annotation>
    <xs:union memberTypes='UnitsEnum UnitsExtType'/>
  </xs:simpleType>
  <xs:simpleType name='NativeUnitsExtType'>
    <xs:annotation>
      <xs:documentation>
        Extended tyoe for The units supported for the source equipment that can
        be converted into MTC Units.
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:pattern value='[a-ln-z][a-z]*:[A-Z_0-9]+'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='NativeUnitsEnum'>
    <xs:annotation>
      <xs:documentation>
        The units supported for the source equipment that can be converted into
        MTC Units.
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:enumeration value='AMPERE'>
        <xs:annotation>
          <xs:documentation>
            amps.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CELSIUS'>
        <xs:annotation>
          <xs:documentation>
            degrees Celsius.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COUNT'>
        <xs:annotation>
          <xs:documentation>
            count of something.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DECIBEL'>
        <xs:annotation>
          <xs:documentation>
            sound level.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEGREE'>
        <xs:annotation>
          <xs:documentation>
            angle in degrees.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEGREE_3D'>
        <xs:annotation>
          <xs:documentation>
            space-delimited, floating-point representation of the angular
            rotation in degrees around the X, Y, and Z axes relative to a
            cartesian coordinate system respectively in order as A, B, and C. If
            any of the rotations is not known, it **MUST** be zero (0).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEGREE/SECOND'>
        <xs:annotation>
          <xs:documentation>
            angular degrees per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEGREE/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            angular acceleration in degrees per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HERTZ'>
        <xs:annotation>
          <xs:documentation>
            frequency measured in cycles per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='JOULE'>
        <xs:annotation>
          <xs:documentation>
            measurement of energy.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='KILOGRAM'>
        <xs:annotation>
          <xs:documentation>
            kilograms.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LITER'>
        <xs:annotation>
          <xs:documentation>
            measurement of volume of a fluid.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LITER/SECOND'>
        <xs:annotation>
          <xs:documentation>
            liters per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MICRO_RADIAN'>
        <xs:annotation>
          <xs:documentation>
            measurement of tilt.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER'>
        <xs:annotation>
          <xs:documentation>
            millimeters.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER_3D'>
        <xs:annotation>
          <xs:documentation>
            point in space identified by X, Y, and Z positions and represented
            by a space-delimited set of numbers each expressed in millimeters.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER/REVOLUTION'>
        <xs:annotation>
          <xs:documentation>
            millimeters per revolution.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER/SECOND'>
        <xs:annotation>
          <xs:documentation>
            millimeters per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            acceleration in millimeters per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='NEWTON'>
        <xs:annotation>
          <xs:documentation>
            force in Newtons.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='NEWTON_METER'>
        <xs:annotation>
          <xs:documentation>
            torque, a unit for force times distance.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OHM'>
        <xs:annotation>
          <xs:documentation>
            measure of electrical resistance.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PASCAL'>
        <xs:annotation>
          <xs:documentation>
            pressure in Newtons per square meter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PASCAL_SECOND'>
        <xs:annotation>
          <xs:documentation>
            measurement of viscosity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PERCENT'>
        <xs:annotation>
          <xs:documentation>
            percentage.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PH'>
        <xs:annotation>
          <xs:documentation>
            measure of the acidity or alkalinity of a solution.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='REVOLUTION/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            revolutions per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SECOND'>
        <xs:annotation>
          <xs:documentation>
            measurement of time.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SIEMENS/METER'>
        <xs:annotation>
          <xs:documentation>
            measurement of electrical conductivity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLT'>
        <xs:annotation>
          <xs:documentation>
            volts.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLT_AMPERE'>
        <xs:annotation>
          <xs:documentation>
            measurement of the apparent power in an electrical circuit, equal to
            the product of root-mean-square (RMS) voltage and RMS current
            (commonly referred to as VA).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='VOLT_AMPERE_REACTIVE'>
        <xs:annotation>
          <xs:documentation>
            measurement of reactive power in an AC electrical circuit (commonly
            referred to as VAR).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WATT'>
        <xs:annotation>
          <xs:documentation>
            watts.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WATT_SECOND'>
        <xs:annotation>
          <xs:documentation>
            measurement of electrical energy, equal to one Joule.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GRAM/CUBIC_METER'>
        <xs:annotation>
          <xs:documentation>
            gram per cubic meter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CUBIC_MILLIMETER'>
        <xs:annotation>
          <xs:documentation>
            geometric volume in millimeters.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CUBIC_MILLIMETER/SECOND'>
        <xs:annotation>
          <xs:documentation>
            change of geometric volume per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CUBIC_MILLIMETER/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            change in geometric volume per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIGRAM'>
        <xs:annotation>
          <xs:documentation>
            milligram.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIGRAM/CUBIC_MILLIMETER'>
        <xs:annotation>
          <xs:documentation>
            milligram per cubic millimeter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLILITER'>
        <xs:annotation>
          <xs:documentation>
            milliliter.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COUNT/SECOND'>
        <xs:annotation>
          <xs:documentation>
            counts per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PASCAL/SECOND'>
        <xs:annotation>
          <xs:documentation>
            pascal per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='UNIT_VECTOR_3D'>
        <xs:annotation>
          <xs:documentation>
            3D Unit Vector. Space delimited list of three floating point
            numbers.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='REVOLUTION/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            revolutions per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='REVOLUTION/SECOND'>
        <xs:annotation>
          <xs:documentation>
            rotational velocity in revolution per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GRAM'>
        <xs:annotation>
          <xs:documentation>
            gram.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='METER/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            acceleration in meters per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='COULOMB'>
        <xs:annotation>
          <xs:documentation>
            electric charge in coulombs (C).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CENTIPOISE'>
        <xs:annotation>
          <xs:documentation>
            measure of viscosity.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DEGREE/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            rotational velocity in degrees per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FAHRENHEIT'>
        <xs:annotation>
          <xs:documentation>
            temperature in Fahrenheit.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FOOT'>
        <xs:annotation>
          <xs:documentation>
            feet.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FOOT/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            feet per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FOOT/SECOND'>
        <xs:annotation>
          <xs:documentation>
            feet per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FOOT/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            acceleration in feet per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='FOOT_3D'>
        <xs:annotation>
          <xs:documentation>
            point in space identified by X, Y, and Z positions and represented
            by a space-delimited set of numbers each expressed in feet.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GALLON/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            gallons per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='HOUR'>
        <xs:annotation>
          <xs:documentation>
            measurement of time in hours.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INCH'>
        <xs:annotation>
          <xs:documentation>
            inches.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INCH/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            inches per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INCH/SECOND'>
        <xs:annotation>
          <xs:documentation>
            inches per second.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INCH/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            acceleration in inches per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INCH_POUND'>
        <xs:annotation>
          <xs:documentation>
            measure of torque in inch pounds.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INCH_3D'>
        <xs:annotation>
          <xs:documentation>
            point in space identified by X, Y, and Z positions and represented
            by a space-delimited set of numbers each expressed in inches.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='KELVIN'>
        <xs:annotation>
          <xs:documentation>
            measurement of temperature.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='KILOWATT'>
        <xs:annotation>
          <xs:documentation>
            measurement in kilowatt.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='KILOWATT_HOUR'>
        <xs:annotation>
          <xs:documentation>
            kilowatt hours which is 3.6 mega joules.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LITER/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            measurement of rate of flow of a fluid.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            velocity in millimeters per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MINUTE'>
        <xs:annotation>
          <xs:documentation>
            measurement of time in minutes.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OTHER'>
        <xs:annotation>
          <xs:documentation>
            unsupported unit.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='POUND'>
        <xs:annotation>
          <xs:documentation>
            US pounds.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='POUND/INCH^2'>
        <xs:annotation>
          <xs:documentation>
            pressure in pounds per square inch (PSI).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RADIAN'>
        <xs:annotation>
          <xs:documentation>
            angle in radians.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RADIAN/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            velocity in radians per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RADIAN/SECOND'>
        <xs:annotation>
          <xs:documentation>
            rotational acceleration in radian per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='RADIAN/SECOND^2'>
        <xs:annotation>
          <xs:documentation>
            rotational acceleration in radian per second squared.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='BAR'>
        <xs:annotation>
          <xs:documentation>
            pressure in Bar.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TORR'>
        <xs:annotation>
          <xs:documentation>
            pressure in Torr.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MILLIMETER_MERCURY'>
        <xs:annotation>
          <xs:documentation>
            pressure in Millimeter of Mercury (mmHg).
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='PASCAL/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            pascal per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GRAVITATIONAL_FORCE'>
        <xs:annotation>
          <xs:documentation>
            $$MASS\times GRAVITATIONAL_ACCELERATION$$ (g) given in
            `METER/SECOND^2`.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='GRAVITATIONAL_ACCELERATION'>
        <xs:annotation>
          <xs:documentation>
            acceleration relative to earth&apos;s gravity given in
            `METER/SECOND^2`. &gt; Note 1 to entry: At different points on
            Earth&apos;s surface, the free-fall acceleration ranges from 9.764
            to 9.834 m/s2 (Wikipedia: Gravitational Acceleration). The constant
            can be customized depending on the location in the universe. &gt;
            Note 2 to entry: In the standard, it is assumed that Earth&apos;s
            average value of gravitational acceleration is 9.90665 m/s2.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='AMPERE_HOUR'>
        <xs:annotation>
          <xs:documentation>
            electric charge in ampere hour.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CUBIC_FOOT/HOUR'>
        <xs:annotation>
          <xs:documentation>
            change of geometric volume in cubic foot per hour.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='CUBIC_FOOT/MINUTE'>
        <xs:annotation>
          <xs:documentation>
            change of geometric volume in cubic foot per minute.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='NativeUnitsType'>
    <xs:annotation>
      <xs:documentation>
        The units supported for the source equipment that can be converted into
        MTC Units.
      </xs:documentation>
    </xs:annotation>
    <xs:union memberTypes='NativeUnitsEnum NativeUnitsExtType'/>
  </xs:simpleType>
  <xs:simpleType name='CoordinateSystemEnumType'>
    <xs:annotation>
      <xs:documentation>
        The coordinate system to be used for the position
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:enumeration value='MACHINE'>
        <xs:annotation>
          <xs:documentation>
            unchangeable coordinate system that has machine zero as its origin.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WORK'>
        <xs:annotation>
          <xs:documentation>
            coordinate system that represents the working area for a particular
            workpiece whose origin is shifted within the `MACHINE` coordinate
            system. If the `WORK` coordinates are not currently defined in the
            piece of equipment, the `MACHINE` coordinates will be used.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DataItemResetValueExtType'>
    <xs:annotation>
      <xs:documentation>
        Extended tyoe for The reset intervals
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:pattern value='[a-ln-z][a-z]*:[A-Z_0-9]+'/>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DataItemResetValueEnum'>
    <xs:annotation>
      <xs:documentation>
        The reset intervals
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:enumeration value='ACTION_COMPLETE'>
        <xs:annotation>
          <xs:documentation>
            {{term(observation)}} of the {{block(DataItem)}} that is measuring
            an action or operation is to be reset upon completion of that action
            or operation.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ANNUAL'>
        <xs:annotation>
          <xs:documentation>
            {{term(observation)}} of the {{block(DataItem)}} is to be reset at
            the end of a 12-month period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='DAY'>
        <xs:annotation>
          <xs:documentation>
            {{term(observation)}} of the {{block(DataItem)}} is to be reset at
            the end of a 24-hour period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='LIFE'>
        <xs:annotation>
          <xs:documentation>
            {{term(observation)}} of the {{block(DataItem)}} is not reset and
            accumulates for the entire life of the piece of equipment.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MAINTENANCE'>
        <xs:annotation>
          <xs:documentation>
            {{term(observation)}} of the {{block(DataItem)}} is to be reset upon
            completion of a maintenance event.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='MONTH'>
        <xs:annotation>
          <xs:documentation>
            {{term(observation)}} of the {{block(DataItem)}} is to be reset at
            the end of a monthly period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='POWER_ON'>
        <xs:annotation>
          <xs:documentation>
            {{term(observation)}} of the {{block(DataItem)}} is to be reset when
            power was applied to the piece of equipment after a planned or
            unplanned interruption of power has occurred.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='SHIFT'>
        <xs:annotation>
          <xs:documentation>
            {{term(observation)}} of the {{block(DataItem)}} is to be reset at
            the end of a work shift.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='WEEK'>
        <xs:annotation>
          <xs:documentation>
            {{term(observation)}} of the {{block(DataItem)}} is to be reset at
            the end of a 7-day period.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:simpleType name='DataItemResetValueType'>
    <xs:annotation>
      <xs:documentation>
        The reset intervals
      </xs:documentation>
    </xs:annotation>
    <xs:union memberTypes='DataItemResetValueEnum DataItemResetValueExtType'/>
  </xs:simpleType>
  <xs:attributeGroup name='HeaderAttributesType'>
    <xs:attribute name='version' type='VersionType' use='required'>
      <xs:annotation>
        <xs:documentation>
          The document version
        </xs:documentation>
      </xs:annotation>
    </xs:attribute>
    <xs:attribute name='creationTime' type='CreationTimeType' use='required'>
      <xs:annotation>
        <xs:documentation>
          time the file was created.
        </xs:documentation>
      </xs:annotation>
    </xs:attribute>
    <xs:attribute name='testIndicator' type='TestIndicatorType' use='optional'>
      <xs:annotation>
        <xs:documentation>
          Indicates that this was a test document
        </xs:documentation>
      </xs:annotation>
    </xs:attribute>
    <xs:attribute name='instanceId' type='InstanceIdType' use='required'>
      <xs:annotation>
        <xs:documentation>
          The unique instance identifier of this agent process
        </xs:documentation>
      </xs:annotation>
    </xs:attribute>
    <xs:attribute name='sender' type='SenderType' use='required'>
      <xs:annotation>
        <xs:documentation>
          The sender of the message
        </xs:documentation>
      </xs:annotation>
    </xs:attribute>
    <xs:attribute name='deviceModelChangeTime' type='DeviceModelChangeTimeType' use='required'>
      <xs:annotation>
        <xs:documentation>
          A timestamp in 8601 format of the last update of the Device
          information for any device
        </xs:documentation>
      </xs:annotation>
    </xs:attribute>
  </xs:attributeGroup>
  <xs:complexType name='HeaderType'>
    <xs:annotation>
      <xs:documentation>
        provides information from an {{term(agent)}} defining version
        information, storage capacity, and parameters associated with the data
        management within the {{term(agent)}}.
      </xs:documentation>
    </xs:annotation>
    <xs:simpleContent>
      <xs:extension base='xs:string'>
        <xs:attribute name='version' type='VersionType' use='required'>
          <xs:annotation>
            <xs:documentation>
              The document version
            </xs:documentation>
          </xs:annotation>
        </xs:attribute>
        <xs:attribute name='creationTime' type='CreationTimeType' use='required'>
          <xs:annotation>
            <xs:documentation>
              time the file was created.
            </xs:documentation>
          </xs:annotation>
        </xs:attribute>
        <xs:attribute name='testIndicator' type='TestIndicatorType' use='optional'>
          <xs:annotation>
            <xs:documentation>
              Indicates that this was a test document
            </xs:documentation>
          </xs:annotation>
        </xs:attribute>
        <xs:attribute name='instanceId' type='InstanceIdType' use='required'>
          <xs:annotation>
            <xs:documentation>
              The unique instance identifier of this agent process
            </xs:documentation>
          </xs:annotation>
        </xs:attribute>
        <xs:attribute name='sender' type='SenderType' use='required'>
          <xs:annotation>
            <xs:documentation>
              The sender of the message
            </xs:documentation>
          </xs:annotation>
        </xs:attribute>
        <xs:attribute name='bufferSize' type='BufferSizeType' use='required'>
          <xs:annotation>
            <xs:documentation>
              The size of the agent&apos;s buffer.
            </xs:documentation>
          </xs:annotation>
        </xs:attribute>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
  <xs:complexType name='MTConnectErrorType'>
    <xs:annotation>
      <xs:documentation>
        root entity of an {{term(MTConnectErrors Response Document)}} that
        contains the {{term(Error Information Model)}}.
        ![MTConnectError](figures/MTConnectErrors.png
        &quot;MTConnectError&quot;){: width=&quot;0.8&quot;} &gt; Note:
        Additional properties of {{block(MTConnectError)}} **MAY** be defined
        for schema and namespace declaration. See {{sect(Schema and Namespace
        Declaration Information)}} for an {{term(XML)}} example.
      </xs:documentation>
    </xs:annotation>
    <xs:sequence>
      <xs:element name='Header' type='HeaderType'>
        <xs:annotation>
          <xs:documentation>
            provides information from an {{term(agent)}} defining version
            information, storage capacity, and parameters associated with the
            data management within the {{term(agent)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:element>
      <xs:choice minOccurs='1'>
        <xs:element name='Error' type='ErrorType'>
          <xs:annotation>
            <xs:documentation>
              error encountered by an {{term(agent)}} when responding to a
              {{term(request)}}.
            </xs:documentation>
          </xs:annotation>
        </xs:element>
        <xs:element name='Errors' type='ErrorsType'>
          <xs:annotation>
            <xs:documentation>
              {{block(Errors)}} groups one or more {{block(Error)}} entities.
              See {{sect(Error)}}. &gt; Note: When compatibility with Version
              1.0.1 and earlier of the MTConnect Standard is required for an
              implementation, the {{term(MTConnectErrors Response Document)}}
              contains only a single {{block(Error)}} entity and the
              {{block(Errors)}} entity **MUST NOT** appear in the document.
            </xs:documentation>
          </xs:annotation>
        </xs:element>
      </xs:choice>
    </xs:sequence>
  </xs:complexType>
  <xs:complexType name='ErrorsType'>
    <xs:annotation>
      <xs:documentation>
        {{block(Errors)}} groups one or more {{block(Error)}} entities. See
        {{sect(Error)}}. &gt; Note: When compatibility with Version 1.0.1 and
        earlier of the MTConnect Standard is required for an implementation, the
        {{term(MTConnectErrors Response Document)}} contains only a single
        {{block(Error)}} entity and the {{block(Errors)}} entity **MUST NOT**
        appear in the document.
      </xs:documentation>
    </xs:annotation>
    <xs:sequence>
      <xs:element name='Error' type='ErrorType' minOccurs='1' maxOccurs='unbounded'>
        <xs:annotation>
          <xs:documentation>
            error encountered by an {{term(agent)}} when responding to a
            {{term(request)}}.
          </xs:documentation>
        </xs:annotation>
      </xs:element>
    </xs:sequence>
  </xs:complexType>
  <xs:simpleType name='ErrorDescriptionType'>
    <xs:annotation>
      <xs:documentation>
        The text description of the error
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'/>
  </xs:simpleType>
  <xs:simpleType name='ErrorCodeType'>
    <xs:annotation>
      <xs:documentation>
        The error code
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base='xs:string'>
      <xs:enumeration value='UNAUTHORIZED'>
        <xs:annotation>
          <xs:documentation>
            The request did not have sufficient permissions to perform the
            request.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='NO_DEVICE'>
        <xs:annotation>
          <xs:documentation>
            The device specified in the URI could not be found.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='OUT_OF_RANGE'>
        <xs:annotation>
          <xs:documentation>
            The sequence number was beyond the end of the buffer.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='TOO_MANY'>
        <xs:annotation>
          <xs:documentation>
            The count given is too large.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INVALID_URI'>
        <xs:annotation>
          <xs:documentation>
            The URI provided was incorrect.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INVALID_REQUEST'>
        <xs:annotation>
          <xs:documentation>
            The request was not one of the three specified requests.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INTERNAL_ERROR'>
        <xs:annotation>
          <xs:documentation>
            Contact the software provider, the agent did not behave correctly.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='INVALID_PATH'>
        <xs:annotation>
          <xs:documentation>
            The xpath could not be parsed. Invalid syntax.
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='UNSUPPORTED'>
        <xs:annotation>
          <xs:documentation>
            The request is not supported by this implementation
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
      <xs:enumeration value='ASSET_NOT_FOUND'>
        <xs:annotation>
          <xs:documentation>
            The asset ID cannot be found
          </xs:documentation>
        </xs:annotation>
      </xs:enumeration>
    </xs:restriction>
  </xs:simpleType>
  <xs:complexType name='ErrorType'>
    <xs:annotation>
      <xs:documentation>
        error encountered by an {{term(agent)}} when responding to a
        {{term(request)}}.
      </xs:documentation>
    </xs:annotation>
    <xs:simpleContent>
      <xs:extension base='ErrorDescriptionType'>
        <xs:attribute name='errorCode' type='ErrorCodeType' use='required'>
          <xs:annotation>
            <xs:documentation>
              The error code
            </xs:documentation>
          </xs:annotation>
        </xs:attribute>
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>
</xs:schema>