OEM OPM223, Operating Instructions Manual, Page: 41 / 104

OPM223/253 Operation
41
C07-OxM2x3xx-05-06-00-xx-002.eps
Fig. 28: SCS alarm
"
Caution!
Do not remove the standard electrode from the process without Hold! Since SCS is measured
against PML, no contact between the inner conductor and PML triggers an alarm.
PCS alarm (Process Check System)
The function AC is used to check measuring signals for deviations. If the measuring signal
change within an hour is smaller than 0.5% (of full scale value of the selected measuring
range), an alarm (E152) is triggered . The reason for such sensor behaviour can be
contamination, cable rupture or similar.
You can monitor the controller activity with the function CC. A malfunction of the controller is
detected and reported thanks to freely adjustable monitoring times (E154 - E157).
C07-OxM2x3xx-05-06-00-xx-001.eps
Fig. 29: PCS alarm (live check)
A Constant measuring signal = alarm triggered after PCS alarm time has elapsed
!
Note!
• The electrode must be symmetrically connected (with PML) to monitor the reference.
• Any PCS alarm pending is automatically deleted as soon as the sensor signal changes.
• Due to its semiconductor component, the ISFET sensor is sensitive to light and reacts with
measured value fluctuations. For this reason, avoid direct sunlight when calibrating and
operating. Normal ambient light does not have any effect on the measurement.
Alarm threshold monitoring
You can use this function to monitor the measured value for permissible upper and lower limits
and trigger an alarm.
22 mA
A
t