Requirements for use
T
he output signals of the protective device must be analyzed by downstream controllers
in such a way that the dangerous state of the machine is ended safely. Depending on
the safety concept, the signal is analyzed by safety relays or a safety controller, for
example.
DANGER
H
azard 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 that
the safety light curtain can fulfill its protective function.
•
It mus
t be possible to electrically influence the control of the machine
•
The electrical control of the machine must meet the requirements of IEC 60204-1
•
When using a safety controller, different signal levels of both OSSDs must be
detected depending on applicable national regulations or required reliability of the
safety function. The maximum discrepancy time tolerated by the control must be
selected according to the application.
•
The OSSD1 and OSSD2 output signals must not be connected to each other
•
In the machine controller, the signals of both OSSDs must be processed sepa‐
rately
Figure 17: Dual-channel and isolated connection of OSSD1 and OSSD2
•
T
he machine must switch to the safe state at any time if at least one of the two
OSSDs switches to the OFF state.
•
Prevent the formation of a potential difference between the load and the protec‐
tive device. If you connect loads to the OSSDs (safety outputs) that then also
switch if controlled with negative voltage (e.g., electro-mechanical contactor with‐
out reverse polarity protection diode), you must connect the 0 V connections of
these loads and those of the corresponding protective device individually and
directly to the same 0 V terminal strip. In the event of a fault, this is the only way to
ensure that there can be no potential difference between the 0 V connections of
the loads and those of the corresponding protective device.
4 P
ROJECT PLANNING
32
O P E R A T I N G I N S T R U C T I O N S | deTec4 Ex 8022883/2019-03-07 | SICK
Subject to change without notice
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