MKS 902B - Troubleshooting

902B Abs Piezo Operation manual
51
Troubleshooting
Symptom
Possible Cause/Remedy
No digital communication
- Check electrical connections (three wires from transducer to
communication equipment)
- Transducer and communication equipment baud rate
matches
- Use of incorrect transducer address. Try address 254
- Attention characters missing (@)
- Termination characters missing (;FF)
NAK180 is received when
transmitting setpoint commands
- The transducer setup is locked. Refer to disable lock
procedure page 21
Incorrect pressure value
- Other gas present than transducer gas setting or trace of
gas
- Contaminated sensor - Transducer repair required
- Corroded sensor - Transducer repair required
Incorrect pressure value at low
pressure.
- Corroded sensor. Transducer repair required
- Incorrect Vac adjustment has been executed
- Transducer exposed to heat or cooling air stream
Incorrect pressure value at high
pressure.
- Corroded sensor. Transducer repair required
- Incorrect ATM adjustment has been executed
- Other gas or gas trace present than transducer gas setting
Set point relay does not trip
- Setpoint not enabled
- Setpoint value not set to proper value
- Setpoint direction is different than the user expects
- Check electrical connection
- Check part number to see if transducer has setpoint relays
No analog output
- Power supply turned off
- Check electrical connections
Status LED illuminating red
- Sensor element defect - Refer to Service and Repair
page 52