Ams trex™ Device Communicator

Note
The lead set must be used to communicate with a wired or wireless device.
Figure 3-9: HART communication terminals on the Device Communicator
communication module
A. Communicate with an externally-powered HART device
User Guide 
Field Communicator application
September 2021
User Guide 
69

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Figure 3-10: HART communication terminals on the Device Communicator Plus
communication module
A. Power and communicate with a HART device.
B. Communicate with an externally-powered HART device.
Related information
Wiring diagrams for HART devices and the Field Communicator application
Power and connect to a HART device
3.10.2
Wiring diagrams for HART devices and the Field
Communicator application
The Trex unit can communicate with a device from the control room, on the bench, or any
wiring termination point in the loop. Connect the lead set to the Trex unit and to the
communication terminals on the device or across the resistor.
Below each diagram, a table lists the expected prompts from the device connection wizard
and the answers to complete the connection. The prompts appear only if the Field
Communicator application could not automatically detect or connect to the device.
Note
The Trex unit acts as a secondary HART master on a HART loop.
 CAUTION
Remove the USB cable from the Trex unit before connecting to a device.
Field Communicator application
User Guide
September 2021
70
User Guide

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Figure 3-11: Power and connect to a 2-wire HART transmitter
Note
When the Trex unit powers the HART transmitter, an external resistor is not needed. The
Trex unit uses an internal resistor that is automatically used when you enable the Trex unit
to power the transmitter.
Note
Do not insert a resistor in parallel with either the HART+pwr or HART terminals on the Trex
unit, or in parallel with the device's communication terminals. This may prevent
communications.