Piezo • Nano • Positioning

Flexible Integration in Text-Based Programming Languages

Maximum flexibility The operation of PI positioningsystems from external pro- grams running under Microsoft Windows is eased with Dy- namic Link Libraries (DLLs) and COM objects. The drivers which are providedsupport all current program- ming languages (see inset) and all positioning systems from PI. Since the drivers are based onthe uniform PI GCS command set (see page 3), GCS function-ality can be included directly in external programs. The advan- tages of the GCS command set are available whether ac- cessed from the DLL or theCOM object.In addition to direct GCS com- mands, the driver sets also make more complex function- alities—with their own graphi-cal interfaces—available to ex- ternal programs. It is thus pos- sible, for example, to use a DLL function call to include the Wave Editor or Profile Genera- tor, complete with operator dia- logs, in an external program.
Languages Supported by PI Trajectory Profiles
MATLAB Trajectory profiles of arbitrary,
Visual Basic, DelphiC, C++, Python LabVIEW (siehe Seite ) Languages Supported by PI MATLAB Visual Basic, Delphi C, C++, Python LabVIEW (see page 6) Integration of GCS commands likeMOV and POS? in DLL Integration of GCS MOV command in COM object

Support of Controller-Specific Features

Improved Piezo Control:Dynamic Digital Linearization(DDL) Conventional piezo controllerscannot completely avoid phase-shift and tracking errorsin applications with rapid, peri-odic motion. This is due in part to the non-linear nature of the piezoelectric material, the finite control bandwidth and the inherent limitations of P-I (pro-portional-integral) servo-con-trol, which only reacts when a position error is detected. The DDL option, available with recent digital piezo controllers, solves this problem. This tech- nology, developed by PI, re-duces the error between cur-rent and desired position to imperceptible values. The dy- namic linearity and effectively usable bandwidth are thus improved by up to three orders of magnitude. DDL is of benefitto single- and multi-axis appli-cations where motion follows a given trajectory repeatedly (seemeasurement curves). user-defined mathematical func- tions enable complex 2-axismotion. With the Wave Editorand Profile Generator graphical interfaces, standard functions (sine wave, square wave, ramps, scans, etc.) are selected and customized. Depending onthe controller used, either time-and-position data value pairs can be saved (Wave Editor) or complete trajectory profiles with velocity, acceleration and jerk (rate of change of accelera- tion) can be specified (ProfileGenerator).The functionality includes:
Elliptical scan with a XY piezo scannerand standard controller. The outer curve shows the desired position, theinner curve shows the actual motion The same scan as before but with a DDLcontroller. The tracking error is reduced to a few nanometers, desired and actual posi- tion cannot be distinguished in the graph Coordination of two axes,e.g. for applications requir-ing circular motion Saving of defined functionsin the controller The Wave Editor and ProfileGenerator are also available as DLL function calls, which enables their simple integra- tion in external programs.
With the Wave Editor, not only are con-figurable functions like triangle, square,sine wave, etc. available, but also com- plex scans are defined Programming complex func-tions Quick access to common functions (e.g. sine, triangleand square waves ...)
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