Siemens SIMATIC Operating Instructions Manual page 120

Fail-Safe Electronic Modules
8.3 F -Switch PROFIsafe Digital Electronic Module
Wiring Diagram of the Connection of Two Single-Channel Sensors to Two Channels
Two single-channel sensors are connected via two channels to two inputs of the F-module
for each process signal (1oo2 evaluation). The sensors can also be supplied via an external
sensor supply.
In order to achieve SIL2/Category 3 with this wiring, you must install a suitably qualified
sensor, for example, in accordance with IEC 60947.
Assignable Parameters for Use Case 2.2
Set the "Type of sensor interconnection" parameter to "2-channel equivalent" for the
corresponding input.
You can enable or disable the "short-circuit test" parameter. For digital inputs connected to
an external supply, set the "Sensor supply" parameter for the corresponding digital input to
"external". The program will otherwise report a "short circuit" diagnostics event if the "short-
circuit test" is enabled.
1L+
1L+ M
L+ M
Figure 8-27
120
WARNING
Vs1 DI0
S0
Wiring Diagram for F-Switch - Two One-Channel Sensors Connected Via Two Channels,
Internal Sensor Supply
F-Switch
DI1
S1
ET 200pro Distributed I/O System - Fail-Safe Modules
Operating Instructions, 05/2007, A5E00394073-02
Vs2 DI2 DI3