The Trex unit can provide power and control current to simulate a device for a loop check. In this setup, the control system is not providing power to the device. This task is used if the loop will have a 4-wire transmitter.
The Trex unit supplies loop power from the HART + pwr terminals, and Loop Diagnostics lets you control the current on the loop.
Connect the lead set to the
HART + pwr terminals on the Trex unit and to
the unpowered loop.
Connection for providing power and simulating a transmitter
- Analog input.
- On the Loop Diagnostics screen, tap Trex Unit Power.
- Tap Simulate Transmitter with 4 mA.
- Change the current value by pressing the quick buttons or the up and down arrow keys.
- Verify the digital control system is reading the same current value.