Stepper motors give excellent low speed performance and positioning stability compared to DC servo motors. A wide range of 2-phase bipolar stepper motors and associated actuators are commercially available, each with its own characteristics, such as step resolution, peak phase current or voltage, and lead screw pitch. To support such a wide range of motors, the apt™ MST602 stepper drive modules are fully configurable (parameterized) with key settings exposed through the associated software graphical interface panels. Motor step resolution and lead screw pitch can be set for a particular motor/actuator combination, phase currents can be limited to suitable peak powers as required, and limit switch configuration is accommodated through flexible logic settings.
Moreover, relative and absolute moves can be initiated with move profiles, which are set using velocity profile parameters (including acceleration/deceleration). Similarly, homing (zero position datum) sequences have a full set of associated parameters that can be adjusted for a particular stage or actuator. For simplicity of operation, the apt™ software incorporates pre-configured settings for each of the Thorlabs stages and actuators, while still exposing all parameters individually for use with third party stepper motor driven systems.
For convenience and ease of use, adjustment of all key parameters is possible through direct interaction with intuitive software graphical panels. For example, a move to the next position can be initiated by clicking directly on the position display and entering a new value.
Note that all such settings and parameters are also accessible through the ActiveX® programmable interfaces for automated alignment sequences. Refer to the Software tab for further information on the apt™ software support for the MST602 module.
Encoded Feedback - Positioning Accuracy
The MST602 stepper controllers also support encoder feedback on each channel through dedicated quadrature encoded pulse (QEP) inputs. A “built in” algorithm can be enabled to allow the stepper system to reach and maintain an encoded position through a highly configurable iterative move sequence. For custom closed loop algorithms, the apt™ software exposes the encoder position for access through the ActiveX® programmable interfaces.
Full Software GUI Control Suite & ActiveX® Controls Included
A full and sophisticated software support suite is supplied with the MST602 module. The suite includes 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 'Cube' controllers. This single unified software offering allows seamless mixing of any apt™ benchtop, table top, or 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 on the image to the right to download a PDF explaining the benefits and features to system integrators of using the aptTM modular rack system in multi-axis motion control applications
Software Developers Support CD
A developers’ kit is shipped with all of our apt™ series controllers. This additional software support is intended for use by software developers working on large, system integration projects that incorporate apt™ products. The kit contains an extensive selection of useful code samples as well as a library of Video Tutorials.