Four-Axis Controller Tackles Stepper Motors in Lab Equipment

While every manufacturing industry has programmable machine controller needs, laboratories have particularly specialized ones. The controllers need to be quiet, tolerant of temperature changes, and often small in profile, since labs are often restricted in space and dealing with increasing number of applications.

Advanced Control Systems Corp., based in Pembroke, Mass., designs and manufactures stepper motor drivers, servo motor amplifiers, integrated driver/controllers, and standalone programmable controllers specifically for scientific applications. Its MCR series of driver/controllers are offered in both four- and eight-axis models.

Last month, ACS introduced its new MCR-4 rack mount four-axis stepper motor controller that drives and controls four two-phase motors with phase currents from 0.25 to 3.0 A per phase simultaneously from a single board. The MCR-4 performs indexing functions with or without a host computer depending on the user's needs, with internal non-volatile memory storing and executing programmed instruction sets.

ACS President Charles "Chuck" Marshall, Jr. told Design News that while it's not a unique feature, it's a particularly useful one when the user needs to execute repetitive functions.

"With the MCR remote control, the user can step each motor forward or backward with the press of a button," he said. "In addition, a relatively novice user can make alterations to its programmed instruction set, as the commands are rooted in ASCII and are easy to learn and implement."

In the lab, the new MCR-4 is said to at home with control for multi-axis positioners, beamline shutters, and other laboratory control instrumentation. High efficiency and low noise are ideal for a lab setting, but Marshall told Design News that many other industrial applications require these features.

"The MCR-4 can be used in any setting where drive and control of multiple stepping motors is required, including industrial automation and test applications," he said. "The 19-in rack mount form factor is preferred by our laboratory customers, but the MCR-4 will sit nicely on your desktop."

The MCR-4 works in operating temperatures between 32 and 140 degrees F for the specialized environment requirements of lab and industrial customers. In addition, the MCR series offers quick-adjust front-panel controls to make it easier to set and change motor current, idle current, and stepping mode.

"No programming knowledge or software interrogation is required; you simply turn the rotary switch to adjust the new motor configuration," Marshall said. "Changeover can happen in seconds."

The MCR-4 can be built with an optional external manual jog control for applications that require small, controlled movements with short jabs of power at full voltage. It's based on certified scientific software - spec and EPICS driver support - and features Ethernet and RS-232 serial communications.