PI PiezoWalk E-712 - Analog Mode

User Manual
E712T0010, valid for E-712.N1, E-712.1AM, E-712.1AN, .2AN, .3AN
CMo, BRo, 10/31/2024
Physik Instrumente (PI) SE & Co. KG, Auf der Römerstraße 1, 76228 Karlsruhe, Germany page 11 / 40
Phone +49 721 4846-0, fax +49 721 4846-1019, e-mail info@pi.ws, www.pi.ws
Nanostepping mode is selected if the PiezoWalk Driving Mode parameter is set to 1.
Nanostepping mode motion can be commanded as follows, depending on the current servo mode (open-loop or
closed-loop operation selected with SVO command):
 Open-loop operation: Motion is commanded with OSM. OSM accepts floating-point numbers for the number of
steps to be performed. This means that also parts of a complete step cycle can be commanded. Motion does
not end in the “relaxed state”, i.e. the piezo voltage signals are not set to 0 V automatically at the end of motion.
 Closed-loop operation: Motion is commanded with MOV or MVR. There is no switching of the driving mode, i.e.
nanostepping mode remains active all the time.
INFORMATION
Switching to closed-loop operation (set servo on with SVO) is only possible after a relax procedure (simple
relax procedure started with RNP command).
Since the nanostepping mode supports performing parts of a step cycle, motion can be finished anytime inside
one step cycle. As a result, only one of the two piezo actuator pairs of the piezo drive modules may be in contact
with the runner at the end of motion.
3.7 Analog Mode
Motion in analog mode is realized by the shearing components only. All piezo actuators of the piezo drive
modules are in contact with the runner. The travel range is limited by the maximum possible shearing
displacement. Motion resolution depends on the stability of the shearing voltage signals and, in closed-loop
operation, on the sensor resolution.
Fig. 8: Analog motion; only shearing components participate; shown with a NEXLINE® drive
Availability of analog mode motion depends on the current servo mode selection (SVO command) and on the
driving mode selection made by the PiezoWalk Driving Mode parameter. Analog mode motion can therefore be
commanded as follows:
 Open-loop operation: Motion in analog mode is always available. It is commanded with SVA.
 Closed-loop operation: Motion is commanded with MOV or MVR.
If the PiezoWalk Driving Mode parameter is set to full-step mode (0) , the driving mode is automatically
switched to analog mode when the target position is almost reached.
If the PiezoWalk Driving Mode parameter is set to nanostepping mode (1), analog mode motion is not
used in closed-loop operation.