Determining a safe absolute position usually requires using highly complex technology. Pepperl+Fuchs offers much simpler solutions for this process, which are based on a combination of the new PUS evaluation unit with the safePXV or WCS sensors. Safety functions (SF) complying with SIL 3 and PL e can therefore be achieved with minimal integration effort.
The safePXV non-contact absolute positioning system only requires one camera-supported sensor since it provides intrinsic redundancy through multicoloured Data Matrix codes. For linear-guided applications such as monorail conveyors and automated storage and retrieval systems, it offers positioning with millimetre precision over tracks up to 10 kilometres in length.
The rugged WCS position encoding system for absolute positioning in outdoor areas uses a stainless steel code rail with recesses. In the safe version, two U-shaped read heads monitor this rail and ensure reliable detection along track distances of up to 314.5 metres, even in adverse conditions such as those found when operating port cranes.
The redundant signals from the sensors are processed and evaluated by the PUS-F161-B safe evaluation unit via two channels. The device acts as a gateway to the fieldbus. It generates a safe position value (SafePos SF), which it can also use to determine a safely monitored speed (SafeSpeed SF). Applications that integrate the sensors and the evaluation unit are certified according to IEC 61508 for SIL 3 and according to EN 13849 for PL e. They enable quick and easy commissioning through pre-certification and pre-configuration.
