Design And Operation Of The Device - SICK LE20 Instrucciones De Operación

Operating Instructions
LE 20
8 008 685/Q913/2007-05-21
Product description
Fig. 3-1: Maximum configuration of the photoelectric switch system
a = Power supply unit
s = Muting sensors
3.2

Design and operation of the device

The LE 20 safety evaluation unit carries out a periodic safety test
on the connected photoelectric switches and also provides the
photoelectric switch system with additional safety functions, i.e.
restart interlock and external device monitoring. With its additional
muting sensors, the extended LE 20 Muting version is able to
distinguish between objects, which pass through the photoelectric
switches into the hazardous area, and personnel. It allows objects
to enter without stopping the machine.
The devices have the following functions:
LE 20
LE 20-Muting
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
d + f = LE 20 Muting
f = LE 20
Test function
Restart interlock (RES)
External device monitoring (EDM)
Test function
Restart interlock (RES)
External device monitoring (EDM)
Muting
Override
Chapter 3
g = Relay module
h = Photoelectric switch
cascade
GB
2 9 5