Endress+Hauser Liquiline CM44P - Page 143

Liquiline CM44P Diagnostics and troubleshooting
Endress+Hauser 143
No. Message Factory settings Tests or remedial action
S
1)
D
2)
F
3)
976 PFM/PWM value high S On Off Pulse frequency modulation: output signal
exceeded/undershot. Measured value outside the
specified range.
• Sensor in air
• Air pockets in assembly
• Incorrect flow to sensor
• Sensor fouled
1. Clean sensor
2. Check plausibility.
3. Adjust the PFM configuration.
977 PFM/PWM value low S On Off
978 ChemoClean Failsafe S On On No feedback signal detected within the configured
period.
1. Check application.
2. Check wiring.
3. Extend the duration.
990 Deviation limit F On On Redundancy: limit value of percentage deviation
exceeded
991 CO2 conc. range F On On CO
2
concentration (degassed conductivity) outside
the measuring range
992 pH calculation range F On On pH calculation outside the measuring range
993 rH calculation range F On On rH calculation outside the measuring range
994 Difference conduct. F On On Dual conductivity outside the measuring range
1) Status signal
2) Diagnostic message
3) Failure current
12.6.2 Sensor-specific diagnostic messages
The following abbreviations for the various sensor types are used in the table:
• P ... pH/ORP (general, applies for all pH sensors)
• P (glass) ... only applies for glass electrodes
• P (ISFET) ... only applies for ISFET sensors
• C ... conductivity (general, applies for all conductivity sensors)
• C (cond.) ... only applies for sensors with conductive measurement of conductivity
• C (ind.) ... only applies for sensors with inductive measurement of conductivity
• O ... oxygen (general, applies for all oxygen sensors)
• O (opt.) ... only applies for optical oxygen sensors
• O (amp.) ... only applies for amperometric oxygen sensors
• N ... nitrate sensors
• T ... turbidity and solids sensors
• S ... SAC sensors
• U ... interface sensors
• I ... ion-selective sensors
• DI ... disinfection sensors
• Phot ... analog photometer sensors
No. Message Factory settings Sensor
type
Tests or remedial action
S
1)
D
2)
F
3)
002 Sensor unknown F On On All
‣
Replace sensor.
004 Sensor defective F On On All