Ams trex™ Device Communicator

Figure 3-21: Communicate with the THUM adapter powered by a voltage source
Connect the lead set to the yellow and white/black wires.
A. Voltage source.
Device connection wizard prompts
Answer
Do you intend to provide power from the Trex unit?
No
Leads are attached to:
Transmitter
Change Polling Option?
Tap 
Yes
and select 63.
Figure 3-22: Communicate with the THUM adapter powered by a current source
Connect the lead set to the yellow and white/black wires. The 250 Ohm resistor is not
required, but it may be used to verify current.
A. Current source.
User Guide 
Field Communicator application
September 2021
User Guide 
79

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Device connection wizard prompts
Answer
Do you intend to provide power from the Trex unit?
No
Leads are attached to:
Positioner
Change Polling Option?
Tap 
Yes
and select 63.
3.10.4
HART Device List
The Device List displays the devices that the Trex unit has detected. Each device is listed by
its tag and address. The Device List will not display when the Auto-Connect option for the
Field Communicator application is enabled and a device was found at address zero.
Tap a device displayed on the Device List to connect to it.
If a device is not listed, tap 
My Device Not Found
to change the HART polling options.
Figure 3-23: HART Device List
Field Communicator application
User Guide
September 2021
80
User Guide

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3.11
Internal resistors
The Trex unit has internal resistors that can be used when the Trex unit powers a HART
transmitter, or when the HART transmitter is on a 4-20 mA current loop without a resistor.
The resistors are enabled through the device connection wizard in the Field
Communicator application.