Operating Instructions

Diagnostics and troubleshooting iTEMP TMT72
36 Endress+Hauser

Faulty connection to the fieldbus host system
Problem Possible cause Remedy
Device is not
responding.
Supply voltage does not match that
specified on the nameplate.
Check the voltage at the transmitter
directly using a voltmeter and correct.
Connecting cables are not in contact with
the terminals.
Check the contacting of the cables and
correct if necessary.
Electronics unit is defective. Replace the device.
Output current < 3.6
mA
Signal line is not wired correctly. Check wiring.
Electronics unit is defective. Replace the device.
HART
communication is
not working.
Missing or incorrectly installed
communication resistor.
Install the communication resistor (250 Ω)
correctly.
Commubox is connected incorrectly. Connect Commubox correctly.

Error messages in the configuration software
→  38
Application errors without status messages for RTD sensor connection
Problem Possible cause Remedy
Measured value is incorrect/
inaccurate
Incorrect sensor orientation. Install the sensor correctly.
Heat conducted by sensor. Observe the face-to-face length of the
sensor.
Device programming is incorrect
(number of wires).
Change the Connection type device
function.
Device programming is incorrect
(scaling).
Change scaling.
Incorrect RTD configured. Change the Sensor type device function.
Sensor connection. Check that the sensor is connected
correctly.
The cable resistance of the sensor (2-
wire) was not compensated.
Compensate the cable resistance.
Offset incorrectly set. Check offset.
Failure current (≤ 3.6 mA or
≥ 21 mA)
Faulty sensor. Check the sensor.
RTD connected incorrectly. Install the connecting cables correctly
(terminal diagram).
Device programming is incorrect (e.g.
number of wires).
Change the Connection type device
function.
Incorrect programming. Incorrect sensor type set in the Sensor
type device function. Set the correct
sensor type.