The Magnetocode (MCD) absolute rotary encoders feature reliability, accuracy, and adaptability. Now, a new hollow-shaft version of the MCD encoder makes it easy to mount these devices on shafts up to 20-mm dia. The recent devices are available with analog (voltage/current) or digital electrical interfaces. Analog versions are a substitute for traditional potentiometers, offering superior reliability, longevity, and accuracy than units they replace. The measurement technology is based on a rotating magnet and Hall-effect sensors. Unlike traditional potentiometers, there is no contact between these components and no loss of accuracy due to wear or surface contamination. Another advantage is a flexible range-setting feature. With this, the installer can ‘teach’ the device the limits of mechanical motion that will be experienced during operations. Once these limits have been defined – which can involve multiple rotations – the device will self-calibrate so the full range of the electrical output (e.g. 0-5 volts) exactly matches the full range of mechanical movement. This improves the overall accuracy of the control system. Buttons and LEDs on the casing of the analog-output models simplify set-up. MCD encoders are well suited for applications requiring extended multi-turn capabilities (up to 8,192 revolutions). A self-powered rotation-counter (based on Wiegand wire technology) records the number of rotations – even if these occur when there is no power supplied to the sensor.
Digital outputs for MCD encoders include serial (SSI), CANopen and DeviceNet.
MCD encoders are tough. Heavy-duty enclosures protect the measurement components from mechanical loads, shock, and vibration, dust and moisture (up to IP 69K ratings). Hollow-shaft versions have a permanently lubricated steel and brass gear-set for a long, trouble-free service life.
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