Networked servoamp shows: Multiaxis is more than "n×one loop"

The transition from analog to digital servoamplifiers is nearly complete, and the benefits of networked control are now coming to the forefront. The Accelnet family of servoamps from Copley Controls uses a rugged, twisted-pair CAN (controller-area-network) data link; improves multiaxis performance; and significantly reduces multiconductor motion-controller cabling, which adds to installation cost, routing headaches, noise pickup, and miswiring opportunities (Picture). The system targets packaging-automation, automated-medical-test, assembly-system, fabrication, and other applications.

The PC-based CAN bus lets you position the servoamp close to its motor and easily link multiple drives. The DSP-based architecture of the servoamp implements polynomial interpolation of contour paths to maximize system tracking and speed and minimize path jaggedness and network traffic. The overall system can update as many as 16 drive motors with positioning information as quickly as once every 4 msec.

The Accelnet family of amplifiers handles motors with power to 2 hp, voltages of 55 to 180V, and peak currents of 9 to 20A. Copley offers a large library of motion-control software for high- and low-level coding and application development. The vendor also offers a system-commissioning setup mode, which uses algorithms to limit the applied power. This mode helps in powering up systems with many motors, which involves risks due to miswiring, incorrect design assumptions, misbehaving hardware, or other real-world problems. The servoamps measure about 2.6×4.0×1 in. (66×103×25 mm), and prices begin at $330 (small quantities).

Copley Controls Corp, 1-781-828-8090, www.copleycontrols.com.