ICM Group Engineering Services used ICON Technologies to integrate a Sick LMS-400 scanning laser into the SCADA system responsible for a major iron ore loading facility. The laser was used to improve the reliability and precision with which a mechanical gripper could be positioned at the center of the “draw bar” coupling between wagons on a loaded ore train.
The “Laser Gap Spotting” system can reliably measure the length of the draw bar, and calculate its centre, to a precision of better than 1 cm, under a wide variety of natural light conditions. The system is based on a National Instruments cFP-2220 Controller, and is a classic PAC application.
The real-time cFP-2220 combines the ruggedness of a PLC with PC-like programmability. The software application running on the controller must handle complex two-way communications with the LMS-400 laser, decode the large mixed ASCII/binary data packets received from the laser, implement a custom centering algorithm, and exchange position data with the host SCADA system via ModBus.