Function – EUCHNER CES-A-ABA-01B (Unicode) User Manual
Page 6
 
Operating Instructions Safety System CES-A-ABA-01/CES-A-ABA-01B
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Function
The safety system CES-A-ABA... complies with the following safety requirements:
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Category 3, PLe according to EN ISO 13849-1
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Proximity device with self-monitoring type PDF-M according to EN 60947-5-3.
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Redundant design of the circuit in the evaluation unit with self-monitoring. As a 
result, the safety system is still effective even if a component fails.
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When the safety guard is opened and closed, it is checked whether the safety 
system relays open and close correctly.
The CES non-contact safety system consists of three components:
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Coded actuator
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Read head
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Evaluation unit
1 read head may be connected to the evaluation unit CES-A-ABA...
Each delivered 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 read head is fastened to the fixed part of the safety guard and is connected 
to the evaluation unit via a two-core screened cable. 
The actuator fastened to the movable part of the safety guard is moved towards the 
read head by closing the door. When the switch-on distance is reached, power is 
supplied to the actuator by the read head by induction and data can be transferred.
The bit pattern read is compared with the code saved in the evaluation unit; if the 
data matches, the safety outputs (relay outputs) are enabled and the door monitor-
ing output OUT (semiconductor output) is also set HIGH.
Due to the combination of dynamic polling of the actuator and the redundant, di-
verse design of the safety electronics with two safety outputs, the evaluation unit 
will enter the safe state with every detectable fault. 
When the safety guard is opened, the safety outputs switch off the safety circuit 
and the door monitoring output (OUT) is switched LOW. The state of the safety 
outputs is monitored internally by positively driven NC contacts (relay output). 
If an internal fault occurs in the evaluation unit, the safety circuit is switched off, 
the diagnostic output (ERROR) is set HIGH and the ERROR LED illuminates red.
The safety contacts on the safety switch CES can also switch small currents. This 
allows the user to connect the device directly to a safe control system.