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8 Diagnosis, asset management and service
LBR • Two-wire 4 … 20 mA/HART
62273-EN-200520
Code
Text message
Cause
Rectification
DevSpec
State in CMD 48
M503
Measurement reli-
ability too low
The echo/noise ratio is too small
for reliable measurement
Antenna dirty or defective
Check installation and process
conditions
Change polarisation direction
Use instrument with higher sen-
sitivity
Clean the antenna
Byte 24, Bit 3 of
Byte 14 … 24
M504
Error at a device in-
terface
Hardware defect
Check connections
Exchanging the electronics
Send instrument for repair
Byte 24, Bit 4 of
Byte 14 … 24
M505
No echo available
Sensor does not detect an echo
during operation
Antenna dirty or defective
Clean the antenna
Use a more suitable antenna/
sensor
Remove possible false echoes
Optimize sensor position and ori
-
entation
Byte 24, Bit 5 of
Byte 14 … 24
M506
Installation/Setup
error
Error during setup
Check or correct installation and/
or parameter settings
Byte 24, Bit 6 of
Byte 14 … 24
M507
Error in the instru-
ment settings
Error during setup
Error when carrying out a reset
False signal suppression faulty
Carry out reset and repeat setup Byte 24, Bit 7 of
Byte 14 … 24
8.4 Rectify faults
The operator of the system is responsible for taking suitable meas-
ures to rectify faults.
The first measures are:
•
Evaluation of fault messages
•
Checking the output signal
•
Treatment of measurement errors
Further comprehensive diagnostics options are available with a PC/
notebook with PACTware and the suitable DTM. In many cases, the
reasons can be determined in this way and faults rectified.
Connect a multimeter in the suitable measuring range according to
the wiring plan. The following table describes possible errors in the
current signal and helps to eliminate them:
Error
Cause
Rectification
4 … 20 mA signal not stable Fluctuating measured value
Set damping
Reaction when malfunc-
tion occurs
Fault rectification
4 … 20 mA signal