Product category:
Stepper and Servo Drives, Motors, Controls
News Release from: Festo | Subject: CMMS-ST motor controller
Edited by the Engineeringtalk Editorial
Team on 04 September 2007
Stepper motors cut costs
Festo's CMMS-ST controller and EMMS-ST stepper motor combination delivers up to 6.5nm torque and speeds up to 2000rev/min.
Festo has launched an intelligent stepper motor controller which employs encoder-based feedback to deliver true servo functionality using low-cost stepper motor technology The CMMS-ST motor controller, in conjunction with the company's EMMS-ST series stepper motors, enables machine designers and builders to implement high positional accuracy motion control systems extremely cost-effectively
This article was originally published on Engineeringtalk on 5 Mar 2001 at 8.00am (UK)
Related stories
Flexible motor controllers cover wide motor range
Festo's Smart Electric Motor Controllers (SEC) AC305 and AC508 provide design engineers with integrated digital positioning control systems for brushless servomotors
Mini Grippers offer Precision Automation
Automation specialist Festo has launched a range of miniature pneumatic grippers with a focus on high levels of precision.
Designed primarily for cost-sensitive applications that demand servo functionality but don't need high peak speeds, the CMMS-ST controller and EMMS-ST stepper motor combination delivers up to 6.5nm torque and speeds up to 2000rev/min.
It is ideal for single and multi-axis applications with loads up to 20kg.
A key advantage of using closed loop feedback is that the stepper motor is always operating at maximum efficiency and cannot suffer step loss.
If the motor is overloaded, the position controller automatically compensates for following error and maintains position tracking.
This means that it is not necessary to oversize the motor to handle an application's peak torque demands, allowing use of smaller, less expensive units.
Further reading
Micro Grippers are Small but Fast
Festo has extended its portfolio of miniaturised products with the introduction of a range of exceptionally small micro pneumatic grippers designed to save valuable space.
Ultra-Thin Slide Cylinder introduced
Festo has introduced an ultra-thin slide pneumatic cylinder into its miniature cylinder range.
Pneumatic subsystems for automated battery pack
Festo has successfully completed development of pneumatic subsystems for an automated battery pack assembly system designed by Gravatom Engineering Systems Ltd (GESL).
Other operational benefits include better smoothness, lower acoustic noise levels, and absence of mechanical resonance.
Although many stepper drives offer the options of closed loop facilities, these generally only offer alarm functionality in case of step error.
The CMMS-ST offers true servo functionality with full control of current, speed and position.
The CMMS-ST is a complete, ready to run, unit, comprising a positioning controller, power output stage, and all necessary control interfaces.
It features a built-in CANopen fieldbus interface as standard, with all bus settings controlled via front panel DIP switches.
DeviceNet and Profibus interfaces are also available, and are supplied as field-replaceable plug-in modules.
The controller is easy to commission.
All set-up parameters are developed off-line on a PC, using Festo's intuitive Windows-based FCT software, and then downloaded to the controller.
As many as 64 move profiles can be stored on the controller and linked together so that entire motion control sequences can be executed entirely independently of the host PLC.
Additional move profiles can also be specified via fieldbus whenever required.
A novel feature of the CMMS-ST controller is that all parameters and controller firmware can be stored on a plug-in SD card.
This option provides a particularly effective service aid.
A replacement drive can be installed and the SD card swapped into the new drive, obviating any need for re-commissioning.
The CMMS-ST controller accepts industry-standard step-and-direction or +/-10V analogue speed-direction inputs, and features particularly extensive I/O facilities, including dedicated inputs for jog and high-speed position capture signals.
All the I/O facilities are designed for robustness.
They are fully protected against short-circuits, over-voltage and reverse voltage, and use 24V levels throughout, ensuring a high degree of noise immunity and compatibility with virtually all PLCs on the market.
RS232 and RS485 serial communications are provided as standard.
The controller is capable of operating in position, velocity and torque control modes.
It also supports master/slave synchronisation and interpolated positioning for multi-axis applications.
It is designed for use with standard two-phase hybrid stepper motors, and offers full-step, half-step, micro-step and smoothing modes of operation.
The controller's power output stage accommodates motor supply voltages between 24 and 75V DC and can generate up to 12A peak current per phase.
An integral braking resistor can handle up to 500W peak regenerated power.
The EMMS-ST stepper motors are available in three frame sizes and two different stack lengths.
Depending on the model, the motors can provide a holding torque of between 0.5 and 8.6nm, and accommodate speeds up to 3000rev/min.
Each model is available with or without the integral encoder option, and with or without a holding brake. Request a free brochure from Festo ...
• Festo: contact details and other news
• Email this article to a colleague
• Register for the free Engineeringtalk email newsletter
• Engineeringtalk Home Page
