EUCHNER CETx-AS-xxx-AB-xxx (Unicode) - Manual (Page 6)

Operating Instructions Safety Switch CET.-AS-...-AB-...
6
Function
Function of the electronics
Safety switches series CET.-AS permit locking of movable safety guards. They
meet the following safety requirements:
Ì Category 3, PLe according to EN ISO 13849-1 (mounting head upward)
Ì Category 4, PLe according to EN ISO 13849-1 (mounting head downward or
horizontal)
The non-contact safety switch CET.-AS consists of three components:coded actua-
tor (transponder), evaluation unit and read head. The evaluation unit is integrated
into the switch housing with the read head.
Each actuator possesses a unique electronic coding and so is a unique element in
the system used. The code in an actuator cannot be reprogrammed.
The actuator must be assigned to the safety switch by a teach-in process so that
it is detected by the system. This unambiguous assignment ensures a particularly
high level of protection against tampering.
The safety switch with integrated evaluation unit and read head is fastened to the
fixed part of the safety guard.
The actuator attached to the movable part of the safety guard is moved towards
the read head fitted in the safety switch by closing the door. When the switch-on
distance is reached, power is supplied to the actuator by the inductive read head
and data can be transferred.
If the actuator is above the extended lift tappet, the door is closed and the half-
sequence is sent via the AS-Interface bus (state: safety guard closed, guard locking
not active).
When the actuator enters the recess, the bit pattern read is compared with the
stored code in the safety switch. If the data match, the code sequence (state:
safety guard closed, guard locking active).
The bit sequence 0000 is sent via the AS-Interface bus when the safety guard is
opened.
Lift tappet
Slide
Transponder
Spring-
mounted
guard
locking
pin
Recess