Endress+Hauser Levelflex M FMP40 Operating Instructions Manual page 69

Levelflex M FMP40 with HART/4...20 mA
Endress+Hauser
Code Description
W611 Less than 2 linearization
points for channel 1
W621 Simulation ch. 1 on
E641 No usable echo
channel 1 Check calibr.
W650 Signal/noise ratio too low
or no echo
E651 Level in safety distance -
risk of overspill
A671 Linearization ch1 not
complete, not usable
W681 Current ch1 out of range
Possible cause
Number of linearization coordinates
entered < 2
Simulation mode is switched on
Echo lost due to application conditions or
buildup
Probe defective
Noise amplitude too high
Level in safety distance
Linearization table is in edit mode
Current out of valid range
(3.8 mA to 21.5 mA)
Troubleshooting
Remedy
Correct table
Switch off simulation mode
Check basic setup
Clean probe (cf. Operating
Instructions)
Eliminate electromagnetic
interference
Alarm will disappear as soon as the
level leaves safety distance
Perform a reset if necessary
Switch on linearization table
Check calibration and linearization
69