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10 Operation
10.1 Switching state of the outputs
The safety light curtains / light grids have two outputs (OSSDs) on the receiver;
the status depends on the condition of the protected area.
All short-circuits between the outputs or between an output and the current supply
(24 V DC or 0 V DC) are detected by the 1 safety light curtains / light grids as a
fault.
Output
Binary states
Description
OSSD1
1
Condition
protected area clear.
OSSD2
1
OSSD1
1
0
0
Condition
protected area interrupted or fault detected.
OSSD2
0
1
0
10.1.1 The safe state
The safe state is when the output is switched off (zero-current state: logic "0") of
min. one of the outputs (OSSDs).
If one of the outputs is switched off, the subsequent safety-related logic unit must
bring the complete system into the state defined as safe.
10.1.2 The switched state
In switched state the receiver provides a current of 24 V DC (logic "1") to both
outputs.
Output characteristics
The output characteristics follow the characteristics of the input according to
IEC 61496:
Logic "1"
24 V DC
max. 400 mA
Logic "0"
≤ 1.5 V DC
< 0.2 mA
