Operation; Switching State Of The Outputs; The Safe State; The Switched State - IFM OY Series Original Operating Instructions

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
OSSD1
OSSD2
OSSD1 1
OSSD2 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"
Logic "0"
26
Description
1
Condition
protected area clear.
1
0 0
Condition
protected area interrupted or fault detected.
1 0
24 V DC
≤ 1.5 V DC
max. 400 mA
< 0.2 mA