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Servo motors and controls are easy to commission
Published:  06 August, 2008

Festo has launched a range of high-performance servomotors and controllers that, it says, can be configured and commissioned in minutes. The EMMS-AS servomotors and CMMP-AS controllers support closed-loop control of speed, position, current and torque, using absolute encoders.

There are ten synchronous servomotors, in five frame sizes, with single or dual stacks, spanning continuous output torques from 0.26–25.5Nm. The largest can deliver peak torques up to 48Nm at speeds of up to 1,400 rpm.

Festo motor

The controllers come in four ratings: 0.5 and 1kVA for single-phase supplies; and 3 and 6kVA for three-phase supplies. The single-phase controllers offer active power correction and can deliver peak currents of 5 and 10A for up to 5s, while the three-phase models can deliver up to 20 and 40A for up to 3s.

The high peak current capabilities make the controllers suitable for dynamic positioning applications involving fast acceleration and deceleration, as well as for use with linear motors.

The servo controllers are claimed to be particularly easy to commission. All set-up parameters, including complete move profiles defining velocity, acceleration and deceleration, are developed on a PC using Windows-based software, and then downloaded to the controller. Up to 256 move profiles can be stored and linked together, allowing entire motion control sequences to be executed autonomously, without needing a host PLC. Additional move profiles can be specified via fieldbus if needed.

Variable tolerances in the drive system, such as belt expansion or screw gain throughout the stroke of a move, can be preloaded into a lookup table and used for dynamic correction.

An electronic safe torque-off function replaces conventional electromechanical contact breakers with a fail-safe signalling system and power semiconductors in a dual-redundant configuration. It allows simple, low-cost installations, and faster recovery from emergency stops.

The controllers have CANopen interfaces, and RS-232 and RS-485 ports, as standard. Profibus, DeviceNet and Sercos are available as options, as are Ethernet ports.

Analogue (±10V) speed-direction inputs are provided, as well as an input for high-speed position signals, with a response time of less than 1ms. Two encoder inputs and an encoder output support master-slave operation, for appplications such as flying saws and electronic cam operation for duties such as carton folding.