Proximity switches for safety applications

Paul Boughton

IFM Electronic is launching inductive proximity sensors that achieve SIL2 or SIL3 standard according to EN 62061.

Available in M12 (SIL2) or M18, M30 and cube styles (SIL3), these fail-safe sensors have two built-in OSSDs (output signal switching devices). They therefore work with conventional safety relays and safety PLCs.

No special demands such as shielding, twisted wires or separate laying are placed on the industrial standard M12 connection. The sensor is simply connected to existing evaluation units, safety controllers and safe fieldbus systems using a common unscreened four-core cable.

Functional safety is assured with the IFM Electronic fail-safe inductive system; coil damage, component health, cross-monitoring, short-circuit protection - all aspects are continuously checked within the device itself. Any fault, at any time, is instantly signalled.

All fail-safe inductive switches from IFM Electronic are constructed with full redundant and diverse internal circuits, certified by TÜV Rhineland, but otherwise have all the advantages of a conventional inductive sensor: no moving parts, sealing to IP67 and a standard M12 connector.

To ensure that the sensor cannot be readily defeated by any metal object, the sensor has been designed so that the target has in the right place at the right time for switching to occur. When the target is present, any other piece of metal between the switch and the target will cause the output to switch off. Setting the unit is not difficult either, because the LED helps in adjustment, while incorporating a delay to prevent misuse.

IFM Electronic

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