EUCHNER CES-AR-CL2-CH (Multicode) - Manual (Page 6)

Operating Instructions Safety Switches CES-AR-C.2-CH
6
Function
The device meets the following safety requirements:
Ì Category 4, PLe according to EN ISO 13849-1
Ì Redundant design of the circuit in the unit with self-monitoring
Ì This means that the safety system still functions even if an internal component
fails
Ì The switch state of the semiconductor outputs is continuously monitored inter-
nally
Ì Short circuit detection at the safety outputs by pulsed signals
The following switch-on condition applies to safety outputs OA and OB (see also
System status table and the section Typical system times):
Ì Safety guard closed
Ì Both safety outputs (IA and IB) must be on
The system consists of the following components: coded actuator (transponder)
and switch.
Every EUCHNER actuator supplied has an electronic coding (unique coding) that is
read by the read head. Only if a correct coding is detected does the system accept
the actuator. The code in an actuator cannot be reprogrammed.
Unlike systems with unique code detection, on the CES-AR-C.2-CH a specific code is
not polled but instead it is only checked whether the actuator is of a type that can
be detected by the system (multicode detection). There is no exact comparison of
the actuator code with the code defined in the safety switch (unique code detection).
The safety switch 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 read head by induc-
tion and data can be transferred.
If a permissible code is detected, the safety outputs are enabled.
Due to the combination of dynamic polling of the actuator and the redundant,
diverse design of the safety electronics with the two feedback safety outputs, the
safety switch 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 monitoring output OUT is switched off. The state of the safety outputs is
monitored internally by two microprocessors.
If faults are detected, the safety circuit is switched off and the DIA LED illuminates.
In case of devices with a DIA monitoring output, the output is switched on.
The safety switch has a redundant circuit design with self-monitoring. This means
that the safety system is still effective even if a component fails.
The system is designed so that failures will not result in the loss of the safety func-
tion. The occurrence of failures is detected by cyclic self-monitoring at the latest
on the next demand to close the safety contacts (e.g. on starting).