Emerson AMS Trex Device Communicator - Connections to Externally-Powered Transmitters

Connections to externally-powered transmitters
To enable the internal resistors, the Trex unit must be connected to the device/loop in a
specific way.
For externally-powered 2-wire HART devices, the Trex unit must be connected in series. In
the diagram below, the Trex internal resistor is enabled in the HART terminals.
Figure 3-25: Connection for using the Trex internal resistor for an externally-powered
2-wire transmitter
A. Voltage source
For 4-wire transmitters, the Trex unit must be connected in parallel. In the diagram below,
the Trex internal resistor is enabled in the HART terminals.
Figure 3-26: Connection for using the internal resistor for a 4-wire transmitter
A. Voltage source
Field Communicator application User Guide
September 2021
82 User Guide
w ww . . co m
information@itm.com1.800.561.8187