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CANopen PLC with camera controls motion

Published 2011-12-09

Festo (Germany) has introduced a gantry system featuring an image processing system with integrated PLC that steers electric axes. It can be used, for example, if electronic components are to be tested while multiple test places are approached. This gantry unit comes with the electric toothed belt axes (EGC-TB or ELGR) and the camera system SBOI-Q.

THE CAMERA ANALYSES THE IMAGE of the reference data and uses it to calculate the correct position for the X- and Z-axes of the handling unit. It is mounted on the front end of the electric cantilever-handling unit. It takes on complete control of the handling unit due to the integrated PLC with CANopen master functionality. The PLC runs the Codesys software compliant to IEC 61131-3.
With this intelligent camera, there is no need for a relatively slow and expensive high-precision spindle axis to position the gripper unit with the components to be tested or to invest in expensive absolute displacement encoders.
A lower-cost toothed belt axis is sufficient for this application. Precision is required only at the gripping point, not on the entire travel path of the axis. A comparison with spindle axes is impressive: the toothed belt axis even makes travel paths of over eight meters and speeds of 10 m/s possible – with a repetition accuracy of less than 0,04 mm. “A solution with spindle axes could not achieve these values,” said David Bowyer from Festo.
The company also launched the CECC controller featuring CANopen and IO-Link connectivity. The PLC runs Codesys (Version 3.0). The compact control unit provides four IO-Link ports (master) for connection of simple I/O devices. The CANopen interface is intended to connect motion controllers and valve units. The PLC is supported by the Application Composer development software. It separates the programming function for the software specialists from the user function. This means that engineers can concentrate on their specific machine development instead of having to grapple with complex program structures. The application platform conforms to IEC 61131-3, allows to link and to parameterize the modules using special editors. "Ease of operation and reduced complexity, particularly during programming and commissioning, are mega-trends in automation technology. We at Festo and 3S are taking this into account with this project", explains Achim Kottmann, from Festo.