Connecting/Wiring; Connecting Safety-Related Inputs And Outputs - Siemens Sirius 3RK3 System Manual

5.3

Connecting/wiring

5.3.1

Connecting safety-related inputs and outputs

Inputs
To achieve the required performance level or SIL, you can have single-channel or two-
channel interconnection of the inputs of the MSS. The following connection methods are
possible:
● In the case of the single-channel connection method, only one input terminal is assigned
for each sensor.
● In the case of the two-channel connection method, two input terminals are assigned for
each sensor. In mixed operation, both single-channel and two-channel sensors can be
interconnected on one module. Cross-circuit detection is possible.
The number of connectable sensors thus varies according to the connection method. Up to 4
two-channel sensors or 8 single-channel sensors can be connected to the 3RK3 Basic
central unit.
The safety-related inputs can also be used to read standard signals (non-safety-related).
Connection methods of the safety-related inputs with cross-circuit detection
2 x single-channel sensor
T1
T2
IN1 ... IN5
Non-floating sensors
When sensors with non-floating outputs are used, they must not be supplied with power via
test outputs T1 / T2. With this function, cross-circuit detection must be deactivated in the
MSS ES tool.
Modular Safety System 3RK3
System Manual, 10/2008, 926 2530-02 DS 02
1 x two-channel sensor
Test output for IN1, 3, 5, 7
Test output for IN2, 4, 6, 8
Sensor inputs
Description of the hardware
5.3 Connecting/wiring
Single-channel and two-channel sensor
mixed
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