Emerson Rosemount 3144P, Reference Manual

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128
Reference Manual
00809-0100-4021, Rev JA
HART Commissioning
April 2017
HART Commissioning
3.17 Troubleshooting
3.17.1 Overview
If a malfunction is suspected despite the absence of a diagnostics message on the Field Communicator
display, follow the procedures described in
Table 3-2 to verify that transmitter hardware and process
connections are in good working order. Under each of four major symptoms, specific suggestions are
offered for solving problems. Always deal with the most likely and easiest-to-check conditions first.
Advanced troubleshooting information for use with field communicators is available in Table 3-3 on
page 129 .
Table 3-2. HART / 4–20 mA Basic Troubleshooting
Symptom Potential source Corrective action
Transmitter does not
communicate with Field
Communicator
Loop wiring
•
Check the revision level of the transmitter device descriptors (DDs) stored in
your communicator. The communicator should report Dev v4, DD v1
(improved), or reference
“Field Communicator” on page 30 for previous
versions. Contact Emerson Customer Central for assistance.
•
Check for a minimum of 250 ohms resistance between the power supply and
Field Communicator connection.
•
Check for adequate voltage to the transmitter. If a Field Communicator is
connected and 250 ohms resistance is properly in the loop, then the transmitter
requires a minimum of 12.0 V at the terminals to operate
(over entire 3.5 to 23.0 mA operating range), and 12.5 V minimum to
communicate digitally.
•
Check for intermittent shorts, open circuits, and multiple grounds.
High output
Sensor input
failure or connection
•
Connect a Field Communicator and enter the transmitter test mode to isolate a
sensor failure.
•
Check for a sensor open circuit.
•
Check if the process variable is out of range.
Loop wiring
•
Check for dirty or defective terminals, interconnecting pins, or receptacles.
Power supply
•
Check the output voltage of the power supply at the transmitter terminals. It
should be 12.0 to 42.4 Vdc (over entire 3.5 to 23.0 mA operating range).
Electronics module
•
Connect a Field Communicator and enter the transmitter test mode to isolate
module failure.
•
Connect a Field Communicator and check the sensor limits to ensure calibration
adjustments are within the sensor range.
Erratic output
Loop wiring
•
Check for adequate voltage to the transmitter. It should be 12.0 to 42.4 Vdc at
the transmitter terminals (over entire 3.5 to 23.0 mA operating range).
•
Check for intermittent shorts, open circuits, and multiple grounds.
•
Connect a Field Communicator and enter the loop test mode to generate signals
of 4 mA, 20 mA, and user-selected values.
Electronics module
•
Connect a Field Communicator and enter the transmitter test mode to isolate
module failure.