Automatically connect to a HART device

The Field Communicator application can automatically detect and connect to a HART device, without requiring any input from you. When you open the Field Communicator application or when the Connect - Select screen is displayed, the Trex unit checks for the most common connection scenarios and, if possible, connects to the device and displays the device menu.

To use the auto-connect feature, ensure the Auto-Connect option is enabled (Settings > Field Communicator App Settings > Auto-Connect), and the Trex unit is connected to one of the following:

  • A HART device that is on an externally-powered compliant HART loop, and the device is communicating at address zero.
  • A 4-wire HART device that is communicating at address zero. (This may require a resistor across the HART terminals. Check the device documentation for the proper connection.)
  • A WirelessHART device that is powered by its battery, and the device is communicating at address zero.

If the Trex unit cannot automatically connect to the device, tap HART on the Connect - Select screen and follow the prompts from the device connection wizard to connect to the device.

Note: You can disable the Field Communicator application from automatically connecting to a device at address zero. If you disable this option, the Trex unit still detects the device at address zero, but you need to select the device on the Device List to connect and view the device screens. You may also want to disable this option if the Trex unit is connected to a transmitter at address zero with a THUM adapter.