Ams trex™ Device Communicator

3.4
Automatically detect a device
The Field Communicator application can automatically detect a 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, detects the connected device and displays the
Device List. You can then select a device and display its device menu. The auto-detect
feature lets you skip the device connection wizard in the Field Communicator application,
which allows for faster connections to devices.
The Field Communicator application can automatically detect:
•
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 
Wireless
HART device that is powered by its battery, and the device is communicating
at address zero.
Field Communicator application
User Guide
September 2021
54
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.
3.4.1
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 
Wireless
HART 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.