Emerson AMS Trex Device Communicator User Manual page 55

User Guide
3.4.1
3.5
User Guide
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• A powered FOUNDATION fieldbus segment that is actively communicating. The
fieldbus segment must have a host system or a FOUNDATION fieldbus device that is
the Link Active Scheduler (LAS).
While the Trex unit is connecting to the device, the Auto-Detect screen is displayed to
show the status. If you tap Cancel, the Connect - Select screen is displayed and the Trex
unit stops the connection process.
Note
For HART devices, the Field Communicator application can automatically detect and
connect to the device if the Auto-Connect option in the Trex Settings is enabled. If this
option is enabled, the device menu is displayed rather than the Device List.
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.
Connect - Select screen
If the Trex unit cannot automatically detect or connect to the device when you open the
Field Communicator application, the Connect - Select screen is displayed. The Connect -
Select screen is the home screen for the Field Communicator application.
You can do the following on the Connect - Select screen:
www.
Field Communicator application
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September 2021
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