The Powerlinc and the Powerlinc CU are X10 powerline interfaces made by smarthome.com.

Though the Powerlinc CU advertises that it can perform limited functions when disconnected from the computer, XTension does not download commands to this device.

The devices use USB interfaces and so do not require a USB Serial Adaptor.

Since the devices fail to implement a unique serial number in their USB implementation XTension can only connect to 1 of them at a time.