Device description
Leuze electronic GmbH + Co. KG
MSI-SR5B
9
3
Device description
The safety relay serves as a link between one or more safety-related sensors and the machine control.
These sensors may be
• type 4, type 3 or type 2 (self-testing) optoelectronic protective devices (AOPD),
• safety switches,
• safety locking devices,
• E-Stop buttons,
• safety rope switches or
• combinations of these sensors.
The safety relay includes a start/restart interlock that can be activated via the connection terminals, a
contactor monitoring function (EDM) and features two safety-related relay outputs (OSSDs) and LED
displays for status control.
The safety switch uses two terminal groups to connect the sensors and to signal their aggregate data via
the OSSDs. Activation is only possible – taking into account RES and EDM – if the sensors on both chan
-
nels and on both terminal groups are switched on.
If one of the sensors switches off, this causes the OSSDs of the safety relay to shut down immediately.
With appropriate bridging (see table 7.1), the evaluation can be reduced to just one sensor.
The safety system consists of the safety relay and the safety components connected to it. It enables
machines or systems to assume a safe state before persons can be endangered. Through the flexible
evaluation of two – possibly also different – sensors, the safety relay provides a compact, low-cost solution
which, with performance level PL e in accordance with EN ISO 13849-1:2015 and SIL 3 in accordance
with EN 61508-1:2010, satisfies the highest safety level.
Figure 3.1: MSI-SR5B with screw terminals
Figure 3.2: MSI-SR5B with spring-cage terminals
