Ams trex™ Device Communicator

Figure 3-31: THUM adapter wiring with 250 Ohm resistor
2. In the Field Communicator application, tap 
HART
.
3. Tap 
Yes
when prompted if you want the Trex unit to power the device.
4. Tap 
Positioner
.
5. When prompted, change the polling address to 63.
6. Follow any additional prompts to connect to the THUM adapter.
The device menu is displayed.
Related information
HART communication terminals
Wiring diagrams for the Smart Wireless THUM
™
 Adapter and the Field Communicator
application
Disconnect a device
3.13
Connect to an externally-powered HART device
By default, the Trex unit tries to automatically connect to the device at address zero. See
Automatically connect to a HART device
 for more information.
 CAUTION
Remove the USB cable from the Trex unit before connecting to a device.
Note
The Trex unit acts as a secondary HART master on a HART loop.
Procedure
1. Connect the lead set to the HART terminals on the Trex unit and to the
communication terminals on the device. See the HART wiring diagrams topic for
the connection details.
If you want to use the Trex internal resistor, connect the Trex unit is series with the
device.
User Guide 
Field Communicator application
September 2021
User Guide 
87

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2. Open the Field Communicator application.
The Trex unit may automatically detect or connect to the device.
3. If the Trex unit does not automatically connect to the device, tap 
HART
and do the
following:
a) Tap 
No
when asked if you want to provide power from the Trex unit.
b) Select 
Transmitter
or 
Positioner
.
c) Follow any additional prompts.
You may see additional prompts if the Trex unit cannot connect to the
device. For example, you may be prompted to review the polling address if
the device is not at address zero, or to increase loop resistance. The Online
menu or the device dashboard displays, depending on the device type.
d) Tap the device displayed on the Device List.
4. To disconnect a device, tap 
Menu
→
Disconnect
, or remove the lead set.