The Trex unit must have the Device Communicator Plus communication module to power a THUM adapter.
When performing a bench configuration, the THUM adapter should be attached to a device. However, the Trex unit can power a THUM adapter when it is not connected to a HART device.
To connect to a device that has a THUM adapter attached, see Connect to an externally-powered HART device or Power and connect to a HART device.
CAUTION:
Remove the USB cable from the Trex
unit before connecting to a device.