Ams trex™ Device Communicator

Figure 3-17: Connect to an externally-powered HART positioner
A — Current source
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
if the device is not at address zero.
Increase loop current?
Tap 
Yes
to increase the current from 4 mA to
another value, if the device did not initially
communicate.
Related information
HART communication terminals
Connect to an externally-powered HART device
Power and connect to a HART device
Internal resistors
User Guide 
Field Communicator application
September 2021
User Guide 
75

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3.10.3
Wiring diagrams for the Smart Wireless THUM
™
Adapter
and the Field Communicator application
Below each diagram, a table lists the expected prompts from the device connection wizard
and the answers to select to complete the connection.
If you are using a 
Wireless
HART adapter that is not the Smart Wireless THUM adapter,
review its documentation before connecting the Trex unit.
Note
•
Ensure you review the documentation included with the THUM adapter for additional
information.
•
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.
Figure 3-18: Power the THUM adapter without a device attached and use 250 Ohm
resistor
Connect the lead set to the red and black wires.
Device connection wizard prompts
Answer
Do you intend to provide power from the Trex unit?
Yes
Are you providing power to a transmitter or positioner?
Positioner
Select 
Positioner
because the Trex unit
needs to control/limit current due to
the lower value of the resistor.
Change Polling Option?
Tap 
Yes
and select the address for the
THUM adapter.
Field Communicator application
User Guide
September 2021
76
User Guide

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