USBrelay Controller
Allows you to turn on and off each individual (or all) relays on HID-compliant USBrelay modules. Currently supports vendor ID 0x16c0 and product ID 0x05df (DCT-Tech compliant).
Future releases will allow you to configure custom VID and PID as well as optional serial number for the device.
Aimed towards FreeBSD and Mac OS X users.
Usage: relaycontrol relay state
Where relay is either 0 (all relays) or an integer between 1 and 8
And state is either 1 (on) or 0 (off)
Based on the works of Signal 11 Software's HIDAPI @ http://www.signal11.us/oss/hidapi/