Endress+Hauser Liquiline M CM42 - Device & Communication Errors

Diagnostics, troubleshooting CM42-MAA101EBE00
16 Endress+Hauser
3.1.3 Device-specific errors
No current output signal
Cable disconnected or
short-circuited
Disconnect cable and measure directly at device.
Output defective See "Device-specific errors" section.
Fixed current output
signal
Current simulation active Switch off simulation.
Incorrect current output
signal
Total load in current loop too high Measure the voltage directly at the device and
compare to diagrams of the power supply and signal
voltage (→ Technical data, Part 1).
EMC (interference coupling) Check wiring. Determine the reason for the EMC and
eliminate it.
No HART communication
Incorrect CPU module Check nameplate
• HART interface missing
• Device not registered in HART
server
• Load too low (min. 250 
required)
• Line problems
(too long, cross-section too small,
not shielded, shield not
grounded, cores not twisted)
• Several devices configured on
same address
For further information see: www.endress.com/hart
Problem Possible cause Tests and/or remedial measures
Dark display No supply voltage Check if supply voltage applied.
CPU defective Replace CPU, make sure correct version is
used.
Values appear on display
but:
– Display does not
change and / or
– Device cannot be
operated
Module not wired correctly Check modules and wiring.
Impermissible operating system
condition
Switch device off and then on again.
Implausible measured
values
Sensor module defective
First perform tests and take measures as
outlined in "Process-specific errors" section
Test the measuring inputs
1. Instead of connecting the sensor,
connect the Memocheck Sim CYP03D
simulator (accessories,  ä 37).
2. Check whether the value output by the
simulator is also displayed by the
CM42.
Problem Possible cause Tests and/or remedial measures