Cold Cathode Sensor High Voltage; Front Panel Control Lock - MKS HPS 937A Series Owner's Operation And Maintenance Manual

Improper connection, Broken sensor wire - A Pirani, thermocouple, or
Convection Pirani sensor is improperly connected or its sensor wire is broken.
Calibration error - A capacitance manometer is indicating pressure below 0 Torr.

Cold Cathode Sensor High Voltage

The high voltage of cold cathode sensors can be turned on and off in
Pressure mode. See page 55 for more information.

Front Panel Control Lock

When the Controller's front panel controls are locked, all panel functions are
inactive and the Controller remains in Pressure mode. REMOTE is displayed.
Most processing in the Controller, including pressure reading,
protect and control set points and logarithmic output, is
suspended until step 4 is done. Buffered analog ouput and set
point relays continue to work.
To lock or unlock the front panel controls or to display the lock status,
Set Function Select switch to Pressure mode and select the bottom
1
display line (B2) with the Gauge Select switch.
Press and hold the Up push-button while pressing the Down push-
2
button slowly four times. L O C indicates a locked panel, and N O T
L O C on the first two lines indicates that it is not locked.
To change the lock status, hold the Down push-button and then press
3
the Up push-button once. Continuing to push the Up push-button will
not continue to toggle between enabled and disabled states.
4 Release the Down push-button.
After a few seconds, press the Up push-button to return to the
5
pressure function.
The front panel can also be locked or unlocked with optional communications
module commands. See RS232/RS485 Communications Module User's
Manual for more information.
44
937A Multi-Sensor System
Front panel lock
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