The global site of the UK's leading magazine for automation, motion engineering and power transmission
27 February, 2024

Twitter link

Fibre optic servo bus spans 400m

01 January, 2005

Fibre optic servo bus spans 400m

In 2002, GE Fanuc Automation decided to make a concerted attack on the motion controls market, using a combination of its own control technology and drives produced by its co-owner, Fanuc. At the recent SPS/IPC/Drives show in Germany, it demonstrated some of the first fruits of this strategy.

The key component so far is a four-axis motion controller which communicates by fibre optics to servo motors that can be daisy-chained together over a distance of up to 400m. The DSM324i controller is tightly integrated with GE Fanuc`s PACSystems RX31 programmable automation controller, although it can also be used with an industrial PC or a Series 90-30 PLC.

The 32-bit controller can be used in a centralised or a distributed architecture and offers a choice of incremental or absolute positioning feedback. An electronic gearbox or cam function can follow a master encoder, another axis, or a time-based master source in the control module.

The fibre optic servo bus allows the system`s "almost dumb" servo amplifiers to be up to 100m apart. It is said to cut wiring costs and, unlike Sercos, does not need to be configured.

Fanuc has produced a new range of servo motors to match the controllers. Their built-in encoders incorporate electronic identification boards, which allow plug-and-play installation.

The motors, spanning torque ratings from 0.2-22Nm, are said to be smaller, faster, and more powerful than their predecessors, while operating with a lower inertia. The smallest model is 60mm long including its absolute encoder, and has a flange width of 40mm. It has a top speed of 5,000 rpm.

Fanuc Already produces 60,000 servo motors every month and is planning to step its output up to 100,000 a month this year.

In the next phase of its motion developments, GE Fanuc plans to integrate a multi-axis controller with a PAC system controller and offer motion programming based on PLCopen standards. It is also planning to support interfaces such as Sercos and Profibus Motion.

  • To view a digital copy of the latest issue of Drives & Controls, click here.

    To visit the digital library of past issues, click here

    To subscribe to the magazine, click here



"Do you think that robots create or destroy jobs?"



Most Read Articles