QNP3 Hardware Manual
Maintenance
4.4. Troubleshooting
Table 4-1:
Troubleshooting
Symptom
Possible Cause and Solution
Stage will not move
l
Improper electrical connection. Check stage and drive connections.
l
Controller trap or fault (refer to controller documentation).
Stage oscillates or
squeals or gives a fault
when the servo is
turned on
l
Servo gains and filters improperly configured for payload. Switch to servo
off mode and make adjustments based on controller documentation (refer to
the online help “Configuring the Servo Loop for a Piezo Stage”).
l
Improper controller parameters (refer to controller documentation)
Travel is reduced after
exposure to high tem-
peratures or a long idle
period
l
Piezo actuator has lost polarization. Re-pole in accordance with
Stage disables and/or
faults at the end of
open-loop travel
l
Stage is driving into End-Of-Travel limit because of a heavy load condition.
Restrict the commanded voltage range or change the Voltage Clamps in the
stage parameter file to avoid entering the limit. Alternately, changing the
stage orientation may prevent it from entering the limit.
l
Stage is driving into an End-Of-Travel limit because it is being held at a
voltage extreme. Restrict the commanded voltage range or change the
Voltage Clamps in the stage parameter file to avoid entering the limit.
Stage disables or faults
inside normal closed-
loop travel range
l
Stage travel has shifted because of a heavy load condition. Run the
AbsoluteFeedbackOffset Calculator to center the stage in its working range.
l
Travel limits are configured incorrectly in the controller. Consult Aerotech
for proper limit settings.
www.aerotech.com
Chapter 4
37
