Beckhoff Automation

July 24, 2005
Drive I/O fits fieldbus

Drive I/O Fits Fieldbus
The KL2531 and KL2541 stepper motor bus terminals integrate a compact motion control solution for small stepper motors up to 200 W, eliminating the need for remote amplifiers. Both terminals can be used just like standard I/O in all common fieldbuses. Interface programming is no longer required.

With a size of only 12 mm, the KL2531 Bus Terminal covers the lower performance range. The device is designed for simple integration into a 24 V DC control voltage system. With a peak current of 1.5 A per phase, a large number of small drives and axes can be integrated.

The KL2541 modules offer higher performance comparable to that of small servo drives, because with a peak current of 5 A, they can generate an impressive torque of 5 Nm in conjunction with a standard stepper motor. The supply voltage of up to 50 V DC enables high speeds with impressivetorque and mechanical output (up to about 200 W). The KL2541 has an integrated incremental encoder interface –despite being only 24 mm wide.

Both stepper motor terminals provide two controlled sine/cosine currents. 25 kHz current control enables smooth current output without resonance. Highly dynamic, low-inductance motors run just as well as stepper motors with small rotor mass. The current resolution is 64 steps per period: 64-fold microstepping. A standard motor with a 1.8° step angle runs very smoothly and can be set to up to 12,800 electronic positions per turn.

The new stepper motor terminals also reduce engineering development time. Both Bus Terminals can be used just like standard I/O in all common fieldbuses. In addition, more demanding positioning tasks can be addressed via the Beckhoff TwinCAT automation software. Like other axes, both Bus Terminals are integrated via the TwinCAT System Manager and the stepper motors can be used like "normal" servo axes.