Ams trex™ Device Communicator

 WARNING
The Loop Diagnostics application is a generic tool that, if misused, can interfere with an
operating HART loop or may damage the ammeter in the Device Communicator Plus
communication module. Do not provide Trex power or current on a loop that is in
operation. Do not provide external power directly across the Trex mA terminals because
this may damage the ammeter.
4.1
Open or close the Loop Diagnostics application
Procedure
1. To open the Loop Diagnostics application, tap the 
Loop Diagnostics
icon on the
Trex Home screen.
2. To close the Loop Diagnostics application, tap 
Exit
.
If you enabled the Trex unit to power a device, the Trex unit stops providing power
when you close the Loop Diagnostics. If the Trex unit was powering a positioner, the
application prompts you to select a current value for the positioner before the
application closes. This allows you to move the positioner to a safe position. After
the selected current value is reached, the Trex unit stops providing power.
User Guide 
Loop Diagnostics application
September 2021
User Guide 
125

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4.2
Loop Diagnostics screen
The 
Loop Diagnostics
screen is divided into three sections:
Loop Diagnostics application
User Guide
September 2021
126
User Guide

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Figure 4-1: Loop Diagnostics screen at start up
A.
Measurement section
: Displays the measured voltage and current. The
measurements begin when the 
Loop Diagnostics
 screen is displayed, and the
measurements update about once per second. See 
Voltage and current measurements
in Loop Diagnostics
 for more information about the terminals used for each
measurement.
B.