
E-664 LVPZT Position Servo Controller User Manual PZ 99E
5. Adjustment and Calibration Procedures
CAUTION: If you inform PI about your application,
your E-664 will be fully calibrated before being
shipped. It is usually not necessary for you to do
anything more than adjust the zero point before
operating the system.
Calibration should only be done after consultation
with PI, otherwise internal configuration settings
may be destroyed.
Procedures which involve opening the case are to
be carried out by qualified authorized personnel
only.
For most applications, only the zero point has to be realigned from time to time to
compensate for temperature changes. Further adjustments are not required and
not recommended as long as system components are not exchanged or modified.
Therefore calibration should only be done if the controller/actuator configuration is
changed or elements are replaced.
The full calibration and adjustment procedure includes static calibration (zero point
and sensor gain adjustment) and dynamic calibration (servo-loop, slew rate and
step response).
5.1. Static Calibration
Proper static calibration makes it possible to accurately drive the PZT system to
absolute positions with an external analog control signal running over a 10 V range
and without reaching the output voltage limits of the amplifier and causing overflow
conditions.
Static calibration consists of zero-point adjustment and static gain adjustment The
adjustments are to some degree interdependent and should be repeated until
stable settings are obtained.
Note: Zero-point adjustment is the only calibration operation regularly required in
most application environments.
The following subsections describe the static calibration procedure for one
channel. Note that calibration must be performed separately on each channel.
5.1.1. Zero-Point Adjustment
Proper zero-point adjustment ensures that the full output voltage swing of the
amplifier can be used without reaching the output voltage limits of the amplifier and
causing overflow conditions, both in open-loop and closed-loop operation.
The zero-point is adjusted with the ZERO potentiometer accessible on the front
panel. This potentiometer shifts the output of the sensor processing circuitry and
hence the values on the "Sensor Monitor" and servo-loop sensor-input lines
1 Before powering up the system, make sure the PZT actuator is mounted in the
same way and with the same load as during normal operations in the
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