The control that is connected and all devices responsible for safety must comply with
the required performance level and the required category (for example, according to
ISO 13849-1).
4.4.1
OSSDs
Safety switches with local inputs and outputs can be directly integrated into the
machine controller.
DANGER
Hazard due to lack of effectiveness of the protective device
In the case of non-compliance, it is possible that the dangerous state of the machine
may not be stopped or not stopped in a timely manner.
b
Make sure that the following control and electrical requirements are met so the
protective function can be fulfilled.
•
The output signals from an OSSD pair must not be connected to each other.
•
In the machine controller, both signals from an OSSD pair must be processed sep‐
arately.
Figure 4: Dual-channel and isolated connection of OSSD 1 and OSSD 2
•
The machine must switch to the safe state at any time if at least one OSSD in an
OSSD pair switches to the OFF state.
4
PROJECT PLANNING
14
O P E R A T I N G I N S T R U C T I O N S | MLP1
8020169/ZJN1/2018-03-21 | SICK
Subject to change without notice
