Emerson AMS Trex - Enable or Disable the Internal Resistors

Connection for using the Trex internal resistor for an externally-
powered 2-wire transmitter
Figure 3-25:
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.
Connection for using the internal resistor for a 4-wire transmitterFigure 3-26:
A. Voltage source
3.11.1 Enable or disable the internal resistors
If the Trex unit is powers the transmitter, there is no prompt/option to enable or disable
the internal 167 Ohm resistor. The Trex unit automatically applies the resistor when you
enable power to a transmitter from the device connection wizard.
Field Communicator application
76 User Guide