User Manual
E727T0005, valid for E-727
BRO, 2019-06-28
Physik Instrumente (PI) GmbH & Co. KG, Auf der Roemerstrasse 1, 76228 Karlsruhe, Germany
Page 134 / 240
Phone +49 721 4846-0, Fax +49 721 4846-1019, Email
Servo-Controller Dynamic Tuning
If the E-727 and the attached stage(s) are ordered together and if PI has sufficient knowledge of
your application, then the parameters of notch filters and standard control algorithm (servo
parameters) will be set to suitable values at the factory, and, if present, saved in the stage's ID-
chip. Modifications of those parameters may, however, be necessary if the load applied to the
stage is changed.
Parameters to be Modified
The following parameters may need to be modified in the E-727:
Settings for notch filters 1 and 2:
Notch frequency 1 (parameter ID 0x08000100), notch frequency 2 (parameter ID
0x08000101)
To determine the resonant frequencies and set the notch filters properly, observe the
system response to an impulse in open-loop operation (p. 136).
Note that by default, the notch filters are enabled only in closed-loop operation.
Servo-control parameters:
P-term (parameter ID 0x07000300), I-term (parameter ID 0x07000301):
Normally the proper P-term and I-term settings are found by observing the response of
the axis to an abrupt change of the control value (step response) in closed-loop
operation (p. 140).
General Notes on Servo-Controller Dynamic Tuning
NOTICE
Damage to the stage and the load from oscillations!
Unsuitable settings of the notch filters and the servo-control parameters of the E-727 can cause
the stage to oscillate. Oscillations can damage the stage and/or the load affixed to it. If the stage is
oscillating (unusual operating noise):
1.
Immediately switch off the servo mode or disconnect the E-727 from the power source.
2.
Only switch on the servo mode after you have modified the settings of the notch filters and
the servo-control parameters of the E-727.
Before you change parameter values of the E-727, create a backup file. See "Creating
Backup Files for Controller Parameters" (p. 53) for more information.
Enter the password “advanced” when prompted to change to command level 1.
For stages with ID-chip, to make the optimized settings available in the future, the
option "Power Up Read ID-Chip" must have "disabled" as its power-on default (value
of parameter 0x0F000000 = 0 in nonvolatile memory). See "ID-Chip Support / Stage
Replacement" (p. 131) for more information.