Safe draw-wire sensor
The SGH50 by Siko (German) provides CANopen, CANopen Safety, and J1939 connectivity. The safety version achieves a performance level (PL) of d.
The draw-wire sensor based on an encoder uses a cable mechanism for absolute measurement of hydraulic or telescopic cylinders. It allows measuring distances up to 5 m. Target applications include agricultural machinery, construction machines, municipal vehicles, forestry machines, piston accumulators, and other industrial applications. It is particular intended for telescopic and hydraulic cylinder applications in mobile machines.
The company offers the SGH25 for measurements up to 2,5 m and SGH10 for up to 1 m. The SGH50 features a special plastic developed for the purpose, which is characterized by an extension of fluid temperature resistance from -85 °C to +105 °C. When it comes to shocks and vibrations, too, the SGH50 sets new standards. It meets the specifications of the vibration standards, which are also used for testing helicopter turbines, and easily copes with shocks 100 times the force of gravity. Unlike rod-based sensors, its flexible cable absorbs the vibrations. The hydraulic medium provides additional damping of any vibration.
In order to cope with the harsh conditions of the mobile world, all of the sensors integrated into the cylinder are completely protected from external factors. SGH sensors therefore have a protection rating of IP69K and use KV1H plug connections.
Applications in which functional safety is required can be supplied with redundant SGH50 versions (CAT3, PLd) in accordance with EN 13849. For safety variants, the supplier offers redundant CANopen or J1939 interfaces. Another option is the CANopen Safety interface with one CAN interface.
With the integrated teach-in function, the measurement length of the sensor can be taught individually up to the maximum length. This leads to a significant reduction in the number of variants for OEMs and cylinder manufacturers. With a maximum measuring range of up to 5 m, the cable-based sensor offers significant advantages to cylinder designers as far as manufacturing costs are concerned, as hollow boring of the piston is no longer necessary. Like all models in the SGH series, the SGH50 can also be integrated into telescopic cylinders, which is not usually possible with conventional measurement systems.
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