5/12/2017
TECH-538/D.W.O. 23160
Page 78 of 189
Description of Functions
The parameter “CALIBRATION STATES” available in the “3-1 Transducer Calibration” menu shows the execution of
the calibration functions called during the automatic calibration routine. These functions are described below:
Position Sensor Cal:
The sensor calibration is a self-adjustment that sets the positioner’s Hall-Effect circuitry.
This function appears in the local display as
Sensor Calibration
and
Acal Sensor
.
Low/Zero Cal -
This function serves to set the fail position of the actuator/valve. Initially during this calibration the
valve is driven to the fail position (hard stop). The user will notice full pressure to Outlet Port 2 and zero pressure to
Outlet Port 1. After a short period of time pressure will increase in Outlet Port 1 and the valve will be driven to the
fully energized position and then back to the fail position. At this point the user has the option to select the hard
stop as low (zero) position or to select an arbitrary position as low (zero) position.
This function appears in the local display as
Low/Zero
Calibration and
Acal Lo
.
High/Span Cal -
This function serves to set the fully energized (full travel) position of the actuator/valve.
Initially during this calibration the valve is driven to the fully energized (full travel) position (hard stop).
The user will notice full pressure to Outlet Port 1 and zero pressure to Outlet Port 2. At this point the user has the
option to select the hard stop as the high (span) position or to select an arbitrary position as the high (span)
position. This function appears in the local display as
High/Span Calibration
and
Acal Hi
.
Transducer Cal -
The purpose of this function is to calibrate the positioner’s pressure transducer.
It should be performed only after a manual sensor calibration.
This function appears in the local display as
Transducer calibration
and
Acal Trnd
.
Auto PID Turning -
This procedure will override the positioner control and will modulate the valve in order to
automatically find out the best P (proportional), I (integral) and D (derivative) parameters.
This function appears in the local display as
Auto PID Turning
and
Acal PID
.
