Ams trex™ Device Communicator

 WARNING
•
Do not use the HART + pwr and mA terminals in series when the Trex unit powers a
device.
•
Do not connect the mA terminals (ammeter) in parallel with a powered 4-20 mA
current loop. Ammeters have low resistance. This can disrupt the loop and cause
devices to report incorrect values or positioners to move unexpectedly.
•
Do not connect the mA terminals on the Trex unit to a power supply that is not current
limited to 250 mA. This can blow a fuse inside the Trex unit. The repair/replacement
will need to be completed at an authorized service center.
For best results when using the mA terminals, do the following:
•
Avoid using the ammeter in cold or very hot temperatures. Extreme temperatures can
affect the accuracy of the measurements.
•
Connect the mA terminals on the Trex unit to the "low-side" of the device. See the
example below.
Figure 2-6: "Low-side" ammeter connection
A. Analog output
2.5.2
Install a communication module
 CAUTION
•
Ensure sufficient grounding. Ensure the personnel, working surfaces, and packaging
are sufficiently grounded when handling electrostatically sensitive parts.
•
Avoid touching the pins on the connectors or components. Discharged energy can
affect the modules.
•
Handle the module with care. It is possible to bend the pins on the module's connector.
User Guide 
AMS Trex Device Communicator overview
September 2021
User Guide 
17

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Procedure
1. Turn off the Trex unit.
2. Place the Trex unit face down on a level, secure surface.
3. Place the communication module into the top of the Trex unit, and carefully align
the communication module with the connector on the Trex unit.
4. Gently press the communication module until it is seated properly with the Trex
unit.
5. Tighten the four screws using a screwdriver. Do not over tighten the screws. Use
0.5Nm maximum torque load.
2.5.3
Remove a communication module
 CAUTION
•
Ensure sufficient grounding. Ensure the personnel, working surfaces, and packaging
are sufficiently grounded when handling electrostatically sensitive parts.
•
Avoid touching the pins on the connectors or components. Discharged energy can
affect the modules.
•
Handle the module with care. It is possible to bend the pins on the module's connector.
Procedure
1. Turn off the Trex unit.
2. Place the Trex unit face down on a level, secure surface.
3. Remove any connected lead sets.
4. Loosen the four screws on the module using a screwdriver.
5. Gently lift the communication module straight away from the Trex unit. Do not
slide the communication module.