Posted to News on 9th Mar 2012, 12:39
New normally-closed fail-safe inductive sensors
ifm electronic is launching the GG851S fail-safe inductive sensor that is said to simplify some of the safety-related applications for such sensors by operating normally-closed.
The safe-state, with the outputs high, is given when the target is not present (outside the 10mm enable zone) in the area known as the safe switch-off zone. If a metal object is in the enable zone, the outputs are switched on. It also has a wider operating voltage than earlier versions, allowing operation down to 12V DC.
A gantry crane example can illustrate the operating principle: a fail-safe sensor monitors the position of the crane on the gantry. With a normally-open version, the sensor would need to be damped along the whole travel in order to maintain the safe function; the sensor was undamped only at the stop positions. This new version allows mounting of only one target each at the beginning and the end of the crane track, which saves material and mounting cost.
ifm's GG851S sensor has two OSSD outputs for connection to a safety relay or PLC. The diagnosis of the different operating states is made via LEDs. No special target is required and the GG851S is fully flush-mountable. The fail-safe sensor is certified to ISO 13849-1 PL d, IEC 61508 SIL 2 and IEC 62061 SIL cl2. Connection is via a standard M12 connector, which is available from the EVC range also manufactured to exacting specifications by ifm electronic.
Follow the link for more information about the GG851S fail-safe inductive sensor.
