文档介绍：Components for safety applications
Preventa safety modules
for monitoring single beam safety light devices, type XU2-S
Operating principle
Operating principle (1)
1 XPS-CE safety modules used in conjunction with single beam XU2-S safety light devices (automatic periodic self-
checking, every 5 ms) constitute a type 2 safety light barrier conforming to IEC 1496-1, IEC 1496-2 and prEN 61496 parts
1 and 2.
The connection of 1 to 4 single beam XU2-S safety light devices (PNP or NPN) allows the establishment of a protected
zone up to 1200 mm high and 8 m wide (prEN 999).
When the system is activated, by the mand (in series with the main circuit feedback loop) and all light beams
being made, the main circuit is closed by the two safety relays of the XPS-CE module.
The breaking of one or more light beams trips the main circuit (both safety relays open). Following deactivation of the light
barrier, a solid state PNP output (not a safety output) closes to inform the PLC controlling the process that a mand
signal is required in order to restart the protection circuit.
The restart can only be authorised by a new mand (locking restart function).
An electronic fuse protects the XPS-CE module from external short-circuits. The electronic protection resets automatically
on removal of the fault.
The “muting” function allows the light device to be inhibited. Th