THORLABS MPZ601 User manual

a dvanced p ositioning t echnology
PIEZOELECTRIC CONTROL MODULE
Model Number MPZ601

THORLABS
About the Company
Thorlabs has been an active member of the Photonics community for over 15 years.
We strive to be the ultimate resource for the photonics community-a place to find the
products you need to enable your experiments, as well as the information you need to get
your application working.
Thorlabs designs, develops, and manufactures building blocks for the photonics industry
including equipment for opto-mechanics, motion control, nano-positioning, alignment,
optical components, laser diodes, tunable lasers and vibration isolation systems. In
addition to core photonics building blocks, we now provide system level solutions
including complete OCT and imaging systems.
Trademarks
Windows is a trademark of Microsoft
Corporation.
ActiveX is a trademark of Microsoft
Corporation.
Visual Basic is a trademark of Microsoft
Corporation.
LabVIEW is a trademark of National
Instruments Corporation.
THORLABS is a registered trademark of
Thorlabs Inc.
Revision History
Product Warranty
Opto-Electronics, Control Electronics,
Optics, and Nano-Positioning Product
Lines.
Thorlabs offers a two year warranty on the
above mentioned product lines, provided
normal use and maintenance of the
products and when properly handled and
correctly installed.
Thorlabs shall repair or replace any
defective or nonconforming product as
detailed above. We ask that buyer contact
Thorlabs for a Return Material
Authorization number (RMA #) from our
Customer Service/Returns department in
order to most efficiently process the return
and/or repair.
Products returned for repair that are not
covered under warranty, a Thorlabs
standard repair charge shall be applicable
in addition to all shipping expenses. This
repair charge will be quoted to the
customer before the work is performed.
Issue Date Summary
1 161204 Initial Issue
2 100909 Method Summary

1
Contents
1 For Your Safety ......................................................................................... 3
Safety Information ..........................................................................................................3
Warnings ........................................................................................................................4
Declarations Of Conformity ............................................................................................4
For Customers in Europe .......................................................................................4
For Customers In The USA ....................................................................................4
Waste Electrical and Electronic Equipment (WEEE) Directive .......................................5
Compliance ............................................................................................................5
Waste treatment on your own responsibility ..........................................................6
Ecological background ...........................................................................................6
2 Overview .................................................................................................... 7
APT Rack System Description .......................................................................................7
Introduction ............................................................................................................7
Building Larger Scale Systems ..............................................................................7
Ease of Use ...........................................................................................................8
Software .........................................................................................................................9
Background ............................................................................................................9
APT Server (ActiveX Controls) ..............................................................................9
APT User.exe .......................................................................................................11
APT Config Utility .................................................................................................12
Piezo Controller Description .........................................................................................13
Introduction ..........................................................................................................13
Easy to Use Software ..........................................................................................13
Easily Configured Closed-Loop Operation ...........................................................13
Open Architecture ................................................................................................14
A Complete Motion Control Solution ....................................................................14
Rear Panel Connections ..............................................................................................15
3 Principles of Operation ........................................................................... 16
Piezoelectric Controller .................................................................................................16
The Piezoelectric Effect .......................................................................................16
Hysteresis ............................................................................................................17
Position Sensing and Feedback Control ..............................................................17
continued...

2
4 Operation .................................................................................................19
Manual Operation ......................................................................................................... 19
Operation From The GUI Panel ........................................................................... 19
Piezo Controller Settings Panel .......................................................................... 22
Setting the Position Sensor Zero ......................................................................... 24
Choice of Display Mode ....................................................................................... 24
Detection of Range of Travel ............................................................................... 24
5 Installation and Maintenance .................................................................25
Mechanical Installation ................................................................................................. 25
Siting .................................................................................................................... 25
Environmental Conditions .................................................................................... 25
Identifying Unsafe Equipment .............................................................................. 25
Electrical Installation .................................................................................................... 26
Electrical Connections ......................................................................................... 26
Rear Panel User I/O Connector ........................................................................... 27
Rear Panel Piezo In Connector ........................................................................... 28
Software Installation ..................................................................................................... 29
Connecting The Hardware ................................................................................... 30
Software Upgrades .............................................................................................. 30
Preventive Maintenance ............................................................................................... 31
Safety Testing ...................................................................................................... 31
Cleaning .............................................................................................................. 31
6 Specifications and Associated Products .............................................. 32
Specifications ............................................................................................................... 32
Associated Products .................................................................................................... 32
7 Piezo Control Method Summary ............................................................33

3
Chapter 1
For Your Safety
1.1 Safety Information
For the continuing safety of the operators of this equipment, and the protection of the
equipment itself, the operator should take note of the Warnings, Cautions and Notes
throughout this handbook and, where visible, on the product itself.
The following safety symbols may be used on the equipment:
Warning, risk of danger. Refer to the handbook for details on this hazard.
Warning, risk of electric shock. High voltages present
Equipotentiality (bonding) terminal
Functional (EMC) earth/ground terminal.
The following safety symbols may be used throughout the handbook:
Warning. An instruction which draws attention to the risk of injury or death.
Caution. An instruction which draws attention to the risks of damage to the product,
process or surroundings.
Note. Clarification of an instruction or additional information.
!

4
For Your Safety
1.2 Warnings
• The Equipment, as described herein, is designed for use by personnel properly trained in
the use and handling of mains powered electrical equipment. Only personnel trained in
the servicing and maintenance of this equipment should remove its covers or attempt any
repairs or adjustments.
• If this equipment is used in a manner not specified by the manufacturer, the protection
provided by the equipment may be impaired. Do not operate the instrument outside its
rated supply voltages or environmental range. In particular, excessive moisture may
impair safety.
• This unit is intended for operation from a normal, single phase supply, in the temperature
range 5° to 40°C, 20% to 80% RH.
1.3 Declarations Of Conformity
1.3.1 For Customers in Europe
This equipment has been tested and found to comply with the EC Directives
89/336/EEC ‘EMC Directive’ and 73/23/EEC ‘Low Voltage Directive’ as amended by
93/68/EEC.
Compliance was demonstrated by conformance to the following specifications which
have been listed in the Official Journal of the European Communities:
Safety EN61010: 2001 Installation Category II, Polution Degree II.
EMC EN61326: 1997
1.3.2 For Customers In The USA
This equipment has been tested and found to comply with the limits for a Class A
digital device, persuant to part 15 of the FCC rules. These limits are designed to
provide reasonable protection against harmful interference when the equipment is
operated in a commercial environment. This equipment generates, uses and can
radiate radio frequency energy and, if not installed and used in accordance with the
instruction manual, may cause harmful interference to radio communications.
Operation of this equipment in a residential area is likely to cause harmful interference
in which case the user will be required to correct the interference at his own expense.
Changes or modifications not expressly approved by Thorlabs Ltd could void the
user’s authority to operate the equipment.

5
1.4 Waste Electrical and Electronic Equipment (WEEE) Directive
1.4.1 Compliance
As required by the Waste Electrical and Electronic Equipment (WEEE) Directive of
the European Community and the corresponding national laws, Thorlabs offers all
end users in the EC the possibility to return "end of life" units without incurring
disposal charges.
This offer is valid for Thorlabs electrical and electronic equipment
• sold after August 13th 2005
• marked correspondingly with the crossed out "wheelie bin" logo (see Fig. 1)
• sold to a company or institute within the EC
• currently owned by a company or institute within the EC
• still complete, not disassembled and not contaminated
Fig. 1.1 Crossed out "wheelie bin" symbol
As the WEEE directive applies to self contained operational electrical and electronic
products, this "end of life" take back service does not refer to other Thorlabs products,
such as
• pure OEM products, that means assemblies to be built into a unit by the user (e. g. OEM
laser driver cards)
• components
• mechanics and optics
• left over parts of units disassembled by the user (PCB's, housings etc.).
If you wish to return a Thorlabs unit for waste recovery, please contact Thorlabs or
your nearest dealer for further information.

6
For Your Safety
1.4.2 Waste treatment on your own responsibility
If you do not return an "end of life" unit to Thorlabs, you must hand it to a company
specialized in waste recovery. Do not dispose of the unit in a litter bin or at a public
waste disposal site.
1.4.3 Ecological background
It is well known that WEEE pollutes the environment by releasing toxic products
during decomposition. The aim of the European RoHS directive is to reduce the
content of toxic substances in electronic products in the future.
The intent of the WEEE directive is to enforce the recycling of WEEE. A controlled
recycling of end of life products will thereby avoid negative impacts on the
environment.

7
Chapter 2
Overview
2.1 APT Rack System Description
2.1.1 Introduction
Thorlabs has an extensive range of one-, two- and three-axis controllers for stepper
motor and piezo actuator control. Increasingly, production of optoelectronic
components requires fully automated or semiautomated control of a large number of
mechanical stages. In such applications, it is often more convenient to use a modular
system of controllers to drive a modular system.
The Thorlabs Modular Motion Control System has been developed to meet the
challenges of the modern optoelectronic production environment and provides
unsurpassed ease of installation, reconfiguration, flexibility and upgradability.
The MMR601 modular rack provides a highly functional 12 channel platform within the
‘footprint’ of a 4U high, 19” wide enclosure. With a unified power supply and a USB
communications interface, the APT rack system is easily incorporated into larger
custom applications.
2.1.2 Building Larger Scale Systems
The unrestricted configuration flexibility offered by the APT rack allows any
combination of the 2-channel APT stepper motor controller, piezoelectric driver and
NanoTrak control modules to be fitted for specific nanopositioning and alignment
applications. For example, a system configured to operate our APT606 6-axis
nanopositioning stage, which has six stepper motors and six piezoelectric actuators
with displacement sensors, would require 12 channels of motion control. Using three
stepper motor modules, each with two channels, provides the motor control; using two
piezoelectric controller modules and one NanoTrak controller module would power all
6 of the piezoelectric actuators while also taking advantage of the position sensors.
Additionally, the NanoTrak module provides the full range of features offered by a fully
operational auto-alignment system. All this functionality fits into the single MMR601
chassis that measures just 4U in height.
Please see the documentation supplied with the various module products for further
details.

8
Overview
2.1.3 Ease of Use
The rack system architecture, hardware and software has been skilfully engineered
to provide an efficient and effective solution to complex high channel count
applications.
The APT rack presents a clean, uncluttered front panel, with six rear mounting bays
for the plug-in modules. The backplane of the rack connects all modules and the
control PC via a standard USB bus. This arrangement greatly simplifies the cable
management issues that arise as the number of channels expands.
A flexible and energy efficient integral power supply powers all of the modules
allowing for an adaptable, “mix-and-match” choice of module type, location and
combination. These features greatly enhance ease-of-use, and provide an
unparalleled flexibility for future system upgrades or reconfigurations. Each module is
equipped with an on-board DSP embedded processor; as modules (channels of
operation) are added, processing power is also added, hence the system is able to
maintain maximum operating efficiency even when fully loaded.
Due to the inherent architecture of the system, additional racks can be added to the
USB bus as required, thus allowing multiple, fully automated 6-axis positioning
stages to be combined into a single unified motion control system.
The PC based software that is used to drive the MMR601 system operates from the
same kernel of ActiveX multithreaded server code and associated suite of high level
user applications used to drive our range of APT stand-alone bench top controllers.
This makes it possible to offer effortless code-porting and concurrent control of bench
top and rack controllers.
The APT software is rigorously engineered using modern object oriented techniques,
ensuring programming environment independence and compatibility with a large
number of third party development tools.
All key high level commands, settings and
system parameters are exposed through a set of ActiveX Drivers. These exposed
objects allow the modular electronics system to be 'driven' from applications written by
the user without the need to understand or alter the core system software.
In addition, ActiveX technology is language independent, allowing custom application
development to be undertaken using any language or development system that
supports ActiveX.

9
MPZ601 Piezoelectric Control Module
2.2 Software
2.2.1 Background
A common requirement in many optoelectronic alignment and characterization
applications concerns the implementation of automated positioning sequences.
Typically, such positioning sequences require a series of descrete movements and
measurements to implement an overall solution
The mechanical stage options and drive electronics offered by Thorlabs are ideally
suited to performing all of these individual steps in a variety of different ways.
The key to the APT range of controllers (and associated mechanical products)
concerns the ease and speed with which complete automated alignment systems can
be engineered at the 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 simple USB hubs and cables.
The USB connection flexibility offered by the APT controllers is matched by the
associated product software. All APT controllers are shipped with a sophisticated
multithreaded ActiveX based software control suite. This suite comprises the main
ActiveX based APT Server with a number of utilities including APTUser and
APTConfig. APT Server is the main software 'engine' that runs on the host PC to
provide all necessary APT services such as generation of sophisticated graphical
instrument panels, multiple unit USB communications and multithreaded execution to
enhance system operation and prevent GUI deadlock. Rather than a single monolithic
entity, the APT Server is actually an interoperating collection of ActiveX Controls (or
simply Controls) together with associated support files and libraries. These ActiveX
Controls, developed using leading edge object oriented coding techniques, are the
key to the powerful, flexible and yet extremely easy to use APT control software.
2.2.2 APT Server (ActiveX Controls)
ActiveX Controls are re-usable compiled software components that supply both a
graphical user interface and a programmable interface. Many such Controls are
available for Windows applications development, providing a large range of re-usable
functionality. For example, there are Controls available that can be used to
manipulate image files, connect to the internet or simply provide user interface
components such as buttons and list boxes.
With the APT system, ActiveX Controls are deployed to allow direct control over (and
also reflect the status of ) the range of electronic controller units. Software
applications that use ActiveX Controls are often referred to as 'client applications'.
Based on ActiveX interfacing technology, an ActiveX Control is a language
independent software component. Consequently ActiveX Controls can be
incorporated into a wide range of software development environments for use by
client application developers. Development environments supported include Visual
Basic, Labview, Visual C++, C++ Builder, HPVEE, Matlab, VB.NET, C#.NET
and, via
VBA, Microsoft Office applications such as Excel and Word.

10
Overview
Consider the ActiveX Control supplied for the APT Piezo control module.
This Control provides a complete user graphical instrument panel to allow the Piezo
unit to be manually operated, as well as a complete set of software functions (often
called methods) to allow all parameters to be set and Piezo control operations to be
automated by a client application. The instrument panel reflects the current operating
state of the controller unit to which it is associated (e.g. such as piezo travel). Updates
to the panel take place automatically when a user (client) application is making
software calls into the same Control. For example, if a client application instructs the
associated Piezo Control to move to a particular position, progress is monitored
automatically by changing position readout on the graphical interface, without the
need for further programming intervention.
The APT ActiveX Controls collection provides a rich set of graphical user panels and
programmable interfaces allowing users and client application developers to interact
seamlessly with the APT hardware. Each of the APT controller modules has an
associated ActiveX Control and these are described fully in system online help or the
handbooks associated with the controllers. In addition to the main ActiveX Server, a
number of other utilities are supplied with the APT system, most notably APTUser and
APTConfig. Note that these utilities themselves take advantage of and are built on top
of the powerful functionality provided by the APT ActiveX Server (as illustrated in the
system architecture diagram below).

11
MPZ601 Piezoelectric Control Module
2.2.3 APT User.exe
The APTUser application allows the user to interact with a number of APT hardware
control units connected to the host PC. This program displays multiple graphical
instrument panels to allow multiple APT units to be controlled simultaneously.
All basic operating parameters can be altered and, similarly, all operations (such as
motor moves) can be initiated. For many users, the APTUser application provides all
of the functionality necessary to operate the APT hardware without the need to
develop any further custom software. For those who do need to further customise and
automate usage of the APT modules (e.g. to implement an alignment algorithm), this
application illustrates clearly how the rich functionality provided by the APT ActiveX
Controls are used by a client application. The complete Visual Basic source project is
provided as a useful aid to software developers.

12
Overview
2.2.4 APT Config Utility
There are many system parameters and configuration settings associated with the
operation of the APT Server (ActiveX Controls). Most can be directly accessed using
the various graphical panels and their associated programmable interfaces. However
there are several system wide settings that can be made 'off-line' before running the
APT software. These settings have global effect; such as switching between simulator
and real operating mode, associating mechanical stages to specific motor actuators
and incorporation of calibration data.
The APTConfig utility is provided as a convenient means for making these system
wide settings and adjustments. Full details on using APTConfig are provided in the
online help supplied with the utility.

13
MPZ601 Piezoelectric Control Module
2.3 Piezo Controller Description
2.3.1 Introduction
The APT Modular Piezoelectric Controller is a component of the Thorlabs APT
Modular Motion Control System, and is designed to be fully integrated into larger
systems that also contain our stepper motor drive and NanoTrak™ modules. It
incorporates the latest high speed digital signal processing (DSP), low noise analog
electronics and ActiveX software technology to provide two low noise, fully software
controlled high voltage (0-75V) output channels.
These modular controllers are designed for use in larger scale critical alignment
applications where nanometer level motion control is required. The embedded
software within the control unit itself is responsible for all actuator movement, and an
intuitive desktop computer graphical user interface provides access to these routines.
Any standard desktop computer with a USB port can be used. The advanced software
includes functions to allow internal and external triggering, programmable search and
scan routines, and external inputs. The embedded software can also be upgraded,
thus offering a cost-effective route to enhancing the capabilities of the unit.
The piezo module inherits all of the functionality and drive specifications found in the
equivalent APT bench top unit. Consequently, all software parameters and modes of
operation first pioneered for the bench top controllers are now available in this 19”
rack module format.
2.3.2 Easy to Use Software
The modular APT Piezo controller is supported by the full suite of APTsoftware tools.
Once the software and associated USB drivers for the APT Rack are installed,
immediate control and visualization of the operation of the stepper motor controllers
as well as any other plug-ins that are installed in the system, is achieved using the
APTUser.exe utility
2.3.3 Easily Configured Closed-Loop Operation
The APT piezoelectric controller module's operation is fully configurable
(parameterized) with key settings exposed through the associated graphical interface
panel. Open or closed loop operating modes can be selected ‘on the fly’. 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.
For convenience and ease of use, adjustment of many key parameters is possible
through direct interaction with the graphical panel, or through the ActiveXTM
programmable interfaces that are included with each instrument. This allows the user
to build automated alignment routines in almost any programming language. See
Section 2.2. for a full description of the APT system software and background on the
advantages of the ActiveX Control technology.

14
Overview
2.3.4 Open Architecture
A key benefit of the APT rack system's architecture is that the user interface software
is able to unify the operation of a large number of modules, each performing its own
set of functions in a true object-oriented fashion. By carefully ensuring compatibility in
embedded design, the APT Piezo module is seamlessly supported by the same highly
functional multithreaded ActiveX software suite developed for the bench top
controllers. ‘Out of the box’ user operation is simply an issue of plugging the module
into the USB equipped APT rack, connecting the rack to a PC and running the existing
APT software suite. All software learning need only be considered once, as all
controls, features and concepts are fully portable. An additional benefit to this unified
software approach is the ability to connect, using USB hub technology, multiple APT
racks and bench top units together on a single host PC. This allows seamless mixing
of both standalone and rack based systems in a single custom application with a
single intuitive user interface.
2.3.5 A Complete Motion Control Solution
The key innovation of the APT range of controllers and associated mechanical
products is the ease and speed with which complete automated alignment 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 racks of modules to be connected to a single controller PC using commerical
USB hubs and cables. When planning an alignment application, simply add up the
number and type of drive channels required and connect together the associated
number of APT controllers (modules or bench top units). It is important that the
connection flexibility offered by the APT controllers is then matched by the associated
software. To fulfill this requirement, all APT controllers are shipped with a
sophisticated multithreaded ActiveX based suite of control software routines. This
suite is comprised of the main ActiveX based APT Server along with the APTUser and
APTConfig utilities. For additional details on the functionality of these software tools
please see Section 2.2.

15
MPZ601 Piezoelectric Control Module
2.4 Rear Panel Connections
Fig. 2.1 Rear panel connections
DRIVE CHANNEL 1
HV OUT (SMC connector) – 0 to 75V, 0 to 250mA. Provides the drive signal to the
piezo actuator.
EXT IN (+) and EXT IN (-) (BNC connector) – Differential Inputs. The output from
the HV amplifier circuit can be set to be controlled, in part, by the differential signal
on these two inputs. If the Input Source is set to include a BNC option, the unit sums
this differential signal with any other input sources selected (voltage set using the
GUI panel ‘Output’ control and voltage from an external potentiometer) - see
Section 4.1.2.
PIEZO IN (9-pin D type connector) – For use with piezo actuators with feedback
capability. Two types of feedback signal are supported, AC Strain Gauge and DC
0-10V. The pin function is dependent on the feedback option, set in the Settings
panel, see Section 4.1.2. and Section 5.2.3.
DRIVE CHANNEL 2 – as DRIVE CHANNEL 1.
USER I/O (26-pin D type connector) - The User I/O connector exposes a number of
internal electrical signals. For convenience, a number of logic inputs and outputs are
included, thereby negating the need for extra PC based IO hardware. Using the APT
support software, these user programmable logic lines can be deployed in
applications requiring control of external devices such a relays, light sources and
other auxillairy equipment.
.
HV OUT EXT IN (-)
PIEZO IN USER I/O
DRIVE CHANNEL 1 DRIVE CHANNEL 2
PIEZO IN
EXT IN (+) HV OUT EXT IN (-)EXT IN (+)
Model No.
MPZ601

16
Chapter 3
Principles of Operation
3.1 Piezoelectric Controller
3.1.1 The Piezoelectric Effect
Piezoelectricity is the effect whereby certain types of crystal expand reversibly when
subjected to an electric field.
Although the amount of expansion is usually very small (corresponding to less than
1% strain in the material) it can be controlled extremely finely by varying the strength
of the electric field. Piezoelectric materials therefore form the basis of very high
precision actuators. The resolution of these actuators is effectively only limited by the
noise and stability of the drive electronics. Moreover, the force generated by the
expanding piezo is very large, typically hundreds of newtons.
Perhaps the most useful property of these actuators is their ability to produce
oscillating motion at considerable frequencies, usually limited by the mechanical
system driven rather than by the piezo actuator itself. This ability is used to advantage
in the NanoTrak control system, for example.
The electric field gradient needed to produce a useful amount of expansion is quite
large. Thus to avoid excessive drive voltages, the actuator is constructed as a stack,
consisting of lamina of active material sandwiched among electrodes – see Fig. 3.1.
In this way, the distance from positive to negative electrodes is very small. A large
field gradient can therefore be obtained with a modest drive voltage (75 V in the case
of Thorlabs actuators).
Fig. 3.1 Piezo-electric actuator schematic diagram
expansion
+ve
–ve
drive voltage
piezoelectric
material
electrodes

17
MPZ601 Piezoelectric Control Module
3.1.2 Hysteresis
Despite the very high resolution of piezoelectric actuators, an inherent problem is the
significant amount of hysteresis they exhibit, (i.e., the tendency of the actuator to
reach a final position that lags behind the demand position).
If a cyclic voltage is applied to the actuator the positions reached on the upward
sweep are smaller than those achieved on the downward sweep. If position is plotted
against voltage, the graph describes a hysteresis loop – see Fig. 3.2.
Fig. 3.2 Piezo-electric hysteresis
3.1.3 Position Sensing and Feedback Control
Hysteresis can be eliminated by using a position sensor and feedback loop, i.e., the
sensor measures the position, the circuit subtracts the measured position from the
demand position to get the error, and a proportional-integral feedback loop adjusts the
voltage to the actuator until the error is virtually zero.
Some Thorlabs nanopositioning actuators have position sensing, others do not. The
Piezoelectric control module allows both types to be controlled.
To control an actuator with position sensing, the Piezoelectric control module should
be set to closed-loop mode. To control an actuator without position sensing, the
Piezoelectric Control module should be set to open-loop mode.
Note. An actuator with position sensing can also be driven in open-loop mode if desired,
since the feedback part of the circuit can be switched off. An advantage of open-loop
mode is the greater bandwidth of the system.
Block diagrams for both modes of operation are shown in Fig. 3.3.
voltage
position

18
Principles of Operation
Fig. 3.3 Open loop and closed loop control
The result of using closed-loop control is a linear relationship between demand
(voltage) and measured position – see Fig. 3.4, in contrast to open loop control – see
Fig. 3.2.
Fig. 3.4 Closed loop response
Open loop control
demand amp actuator
moving
part
moving
part
actuator
sensor
amp
a + b/s
+
–
Closed loop control
demand
real position
demand position