Features

• Quiet High Resolution Position Control (for Very Fine Positioning Applications)
• Voltage Ramp and Waveform Generation Capability (for Scanning Applications)
• High Bandwidth (10 kHz) Piezo Positioning
• Auto-Configure Function for Thorlabs Ident Equipped Piezo Actuators
• User Controlled Digital I/O Port
• User I/O Port (Logic Input/Outputs, Potentiometer Input)
• Full Software Control Suite Supplied
• Intuitive Software Graphical Control Panels
• Extensive ActiveX® Programming Interfaces
• Fully Software Integrated with Other apt™ Family Controllers (Integrated Systems Development)

The apt™ MPZ601 piezo driver module is a dual channel high power (75 V, 500 mA) piezo controller. It has been designed to drive the full range of open and closed loop piezo equipped nano-positioning actuators and stages offered by Thorlabs (see Related Items tab). Equipped with strain gauge feedback circuitry on each channel this unit is able to provide closed loop positioning to the nanometer regime when operated with Thorlabs actuators. In addition flexible software settings make these units highly configurable and therefore suitable for driving a wide range of piezo elements in third party products. A waveform generation capability combined with triggering outputs makes this unit particularly suitable for piezo scanning applications.

This module incorporates the latest high speed digital signal processing (DSP) and low-noise analog electronics technology and has been designed specifically to fit the highly flexible apt™ MMR601 Motion Control 19" Modular Rack System. Multiple MPZ601 piezo modules can be fitted to this rack system (providing up to 12 channels of operation per rack) to support larger scale critical alignment applications where nanometer level motion control is required with a high axis count.

USB connectivity via the MMR601 Rack Enclosure provides easy plug and play PC operation - multiple modules can be connected to a single PC via standard USB hub technology for multi-axis motion control applications. Coupling this with the very user friendly apt™ software allows the user to very quickly get up and running in a short space of time – for example all relevant operating parameters are set automatically for Thorlabs piezo actuator products. Advanced custom motion control applications and sequences are also possible using the extensive ActiveX® programming environment described in more detail on the Software and Video Tutorials tabs.

Module Specifications

Flexibility

The MPZ601 piezo driver module is a member of the growing apt™ family of rack, bench top and optical table top motion controllers. It has been designed for use in critical multi-axis alignment applications where manual or automated nanometer level motion control is required. With dual outputs, each drive channel is capable of delivering up to 75V/500 mA and is compatible with all piezo-actuated nanopositioning actuators & stages in the Thorlabs range. The MPZ601 combines the latest high speed digital signal processors (DSP) with low-noise analog electronics and ActiveX® software technology for effortless software controlled piezo motion.

To support such a wide range piezo actuators the apt™ piezo driver module is fully configurable (parameterized) with key settings exposed through software. Intuitive easy to use software graphical panels allows immediate control and visualization of the operation of the piezo controller - adjustment of many key parameters is possible through direct interaction with the graphical panel. Open or closed loop operating modes can be selected on the fly, and in both modes the display can be changed to show drive voltage or position (in microns). In the closed loop operation mode, both the P & I (proportional and integral) components of the feedback control loop can be altered to adjust the servo loop response. The output drive voltage or position can be adjusted by rotating the software-panel control knob.

Note that all such settings and parameters are also accessible through the ActiveX programmable interfaces which allow the user to build automated alignment routines. Refer to the Software tab for further information on the apt™ software support for the MPZ601.

Waveform Output/Triggering

Over and above open and closed loop piezo positioning the DSP controller within the MPZ601 module offers additional and useful functionality. Through software interfaces it is possible to program in a voltage (or position) ramp or waveform as a table of values and then instruct the controller to output (clock out) this table either 'single shot' or continuously. It is possible to specify a hardware output trigger to be generated at a specific point during the waveform output in order to control third party equipment as a function of the piezo voltage (position). Alternatively an external system can trigger the piezo unit to initiate the waveform output in the reverse scenario. This functionality is particularly useful for piezo scanning applications.

Full Software GUI Control Suite and ActiveX® Controls Included

A full and sophisticated software support suite is supplied with the MPZ601 piezo drive module. It comprises a number of out of the box user utilities to allow immediate operation of the unit without any detailed pre-configuration. All operating modes can be accessed manually and all operating parameters changed and saved for next time use. For more advanced custom motion control applications a fully featured ActiveX® programming environment is also included to facilitate custom application development in a wide range of programming environments. Note that all such settings and parameters described above are also accessible through these ActiveX® programmable interfaces. For further information on the apt™ software support refer to the Software tab. Demonstration videos illustrating how to program the apt™ software are also available for viewing from the Video Tutorial tab.

The ActiveX® apt™ system software shipped with this module is also compatible with other apt™ family controllers including our bench top and smaller optical table mountable T-Cube controllers. This single unified software offering allows seamless mixing of any apt™ benchtop, table top and rack based units in any single positioning application.

The key innovation of the apt™ range of controllers and associated mechanical products is the ease and speed with which complete automated alignment/positioning systems can be engineered at both the hardware and software level. All controllers in the apt™ range are equipped with USB connectivity. The multi-drop USB bus allows multiple apt™ units to be connected to a single controller PC using commercial USB hubs and cables. When planning a multi-channel application, simply add up the number and type of drive channels required and connect together the associated number of APT controllers.

Click below to download a PDF explaining the benefits and features to system integrators of using the apt™ modular rack system in multi-axis motion control applications.

User I/O Controller

D-type Female

Piezo Controller

D-type Female

Typical APT User GUI

The APT (Advanced Positioning Technology) family covers a wide range of motion controller products ranging from small low powered single channel optomechanical motor drivers (the 'Cube' drivers) to high power multi-channel modular 19" rack nanopositioning systems (the APT Rack System).

All controllers in the APT family share a common software platform, the APT System Software. The software CD supplied with all controllers contains an installation of this system software, together with a wealth of support information in the form of handbooks, help files, tutorial videos, FAQs and other relevant information on using and programming these Thorlabs products.

By providing this common software platform, Thorlabs has ensured that users can easily mix and match any of the APT controllers in a single application while only having to learn one single set of software tools. In this way it is perfectly feasible to combine any of the controllers from the low powered single axis to the high powered multi-axis systems and control all from a single PC based unified software interface.

The APT System Software allows two methods of usage - graphical user interface utilities (supplied) for direct interaction and control of the controllers out of the box, and a set of programming interfaces that allow custom integrated positioning and alignment solutions to be easily progammed in the development language of choice.

Typical Configuration Screen

Detailed information on both usage modes is provided on the CD.

Also of particular interest is the inclusion on the software CD of a range of software video tutorials (see the Video Tutorials tab). These videos illustrate some of the basics of using the APT System Software from both a non-programming and a programming point of view. There are videos that illustrate usage of the supplied APT utilities that allow immediate control of the APT controllers out of the box. There are also a number of videos that explain the basics of programming custom software applications using Visual Basic, LabView and Visual C++. 

Click here to go direct to the Thorlabs Download Area to access the full APT software CD. Experiment with the software using the simulator mode - refer to the Tutorial Videos for the APTConfig utility to learn how to select simulator mode.

These videos illustrate some of the basics of using the APT System Software from both a non-programming and a programming point of view. There are videos that illustrate usage of the supplied APT utilities that allow immediate control of the APT controllers out of the box. There are also a number of videos that explain the basics of programming custom software applications using Visual Basic, LabView and Visual C++. Watch the videos now to see what we mean.

Click here to view the video tutorial

To further assist programmers, a guide to programming the APT software in LabView is also available.

Click here to view the LabView guide

Piezo Driver Bandwidth Tutorial

Knowing the rate at which a piezo is capable of changing lengths is essential in many high-speed applications. The bandwidth of a piezo controller and stack can be estimated if the following is known:

1. The maximum amount of current the controllers can produce. This is 0.5 A for our BPC Series Piezo Controllers, which is the driver used in examples below.
2. The load capacitance of the piezo. The higher the capacitance, the slower the system.
3. The desired signal amplitude (V), which determines the length that the piezo extends.
4. The absolute maximum bandwidth of the driver, which is independent of the load being driven.

To drive the output capacitor, current is needed to charge it and to discharge it. The change in charge, dV/dt, is called the slew rate. The larger the capacitance, the more current that is needed.

So for example, for a 100 µm stack, having a capacitance of 20 µF, being driven by a BPC Series piezo controller with a maximum current of 0.5 A, the slew rate is given by

Hence, for an instantaneous voltage change from 0 V to 75 V, it would take 3 ms for the output voltage to reach 75 V.

Note: For these calculations, it is assumed that the absolute maximum bandwidth of the driver is much higher than the bandwidths calculated, and thus, driver bandwidth is not a limiting factor. Also please note that these calculations only apply for open-loop systems. In closed-loop mode, the slow response of the feedback loop puts another limit on the bandwidth.

Sinusoidal Signal

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The bandwidth of the system usually refers to the system's response to a sinusoidal signal of a given amplitude. For a piezo element driven by a sinusoidal signal of peak amplitude A, peak-to-peak voltage V_pp, and frequency f, we have:

A diagram of voltage as a function of time is shown to the right. The maximum slew rate, or voltage change, is reached at t = 2nπ, (n=0, 1, 2,...) at point a in the diagram to the right:

From the first equation, above:

Thus,

For the example above, the maximum full-range (75 V) bandwidth would be:

For a smaller piezo stack with 10 times lower capacitance, the results would be 10 times better, or about 1060 Hz. Or, if the peak-to-peak signal is reduced to 7.5 V (10% max amplitude) with the 100 µm stack, again, the result would be 10 times better at about 1060 Hz.

Click to Enlarge

Triangle Wave Signal

For a piezo actuator driven by a triangle wave of max voltage V_peak and minimum voltage of 0, the slew rate is equal to the slope, or:

or, since f = 1/T:

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Square Wave Signal

For a piezo actuator driven by a square wave of max voltage V_peak and minimum voltage of 0, the slew rate limits the minimum rise and fall time. In this case, the slew rate is equal to the slope while the signal is rising or falling. If t_r is the minimum rise time, then:

or