Ethernet cuts motion control wiring

The Californian firm Galil Motion Control claims to have reduced dramatically the amount of wiring needed for multi-motor motion control installations by adopting Ethernet-based communications.

Galil says that its new E-series controllers eliminate the wiring of conventional central or bus-based control systems. They also avoid the complicated programming usually associated with distributed control systems.

A single controller acts as the master or "virtual central controller", receiving motor commands from a host computer and passing them on to slave controllers located next to motors and I/O. Galil says that this arrangement relieves the host computer of the task of co-ordinating axes and synchronising control operations, and cuts costs because each controller can operate two motors.

"Designers who need to control several motors now have a simplified, cost-effective alternative to central or distributed systems," says Galil president, Jacob Tal. "The key advantage is that it meets the design criteria of short localised wiring, simplified programming, low-cost components and efficient communications."

The first controller in the new series, the DMC-3425, is designed to control two servo motors with encoder frequencies up to 12MHz, or one servo and one stepper up to 3MHz. The controllers provide functions such as gearing, and linear or circular interpolation, and include three digital I/O and two analogue I/O (with optional expansion to 64 I/O). Each controller costs $695 in the US.