902B Abs Piezo
Operation manual
15
Setpoint 1 value
50 Torr
Hysteresis 1
40 Torr
Setp.1 Direction
Below
Setp.1 Enable
ON
When using the setpoint relay to control process equipment, always take
appropriate precautions to prevent system damage in case of transducer power
failure. The NC contact will be closed in case of transducer power failure.
If the transducer is supplied as a special version (P/N: 902B-xxxxx-xxxx) with pre-configured
parameters such as setpoint settings, the setup is per default locked. The transducer will reply with
error code “NAK180” if the user tries to change parameters. To change pre-configured parameters
refer to unlock procedure page 21.
Setpoint setup by Serial interface
The correct procedure for setting up set point parameters are:
1. Enter set point value 50 Torr
Command: @253SP1!50;FF
Reply: @253ACK50;FF
2. Select set point direction (ABOVE/BELOW)
Command: @253SD1!BELOW;FF
Reply: @253ACKBELOW;FF
3. Enter set point hysteresis value, if other than default ±10% of set point value is required.
Command: @253SH1!40;FF
Reply: @253ACK40;FF
4. Enable set point (OFF, ON)
Command: @253EN1!ON;FF
Reply: @253ACKON;FF
Setpoint setup by PDR900 Controller
1. Edit > Setpoint > Setpoint Value 1
Enter set point value 50 Torr
2. Edit > Setpoint > Direction 1
Select set point direction
3. Edit > Setpoint > Hysteresis 1
Enter set point hysteresis value
Only if other than default ±10% of set point value is required.
4. Edit > Setpoint > Enable 1
Enable set point
Setpoint value
The setpoint value is the pressure either below or above which the setpoint relay will be energized.
Setpoint hysteresis value
The hysteresis value is the pressure value at which the setpoint relay will be de-energized.
Setpoint direction
The setpoint direction determines whether the relay is energized above or below the set point value.
Enable setpoint
The enable setpoint command enables, disables or assigns the setpoint relay to absolute Piezo
measurement.
The 902B transducer has an auto hysteresis setting of 10% of the set point value that
overwrites the current hysteresis value whenever the set point value or set point
direction is changed. If other hysteresis value than 10% is required, first set the set
point value and set point direction before setting hysteresis value.