Siemens SIMATIC Operating Instructions Manual page 76

Fail-Safe Electronic Modules
8.1 8 /16 F-DI DC24V PROFIsafe Digital Electronic Module
Wiring Diagram for Use Case 2.3 – Connecting Two One-Channel Sensors Nonequivalently Via Two
Channels
Two one-channel sensors are connected nonequivalently via two channels to two inputs of
the F-I/O module for each process signal (1oo2 evaluation).
The left channels on the F-module (DI 0 to DI 2, DI 0 to DI 3, or DI 8 to DI 11) supply the
wanted signals. If no faults are detected, these signals will be available in the I/O area for
inputs in the F-CPU.
The sensors can also be supplied via an external sensor supply.
The figure below illustrates an example wiring diagram for channel groups 1 and 2.
Figure 8-12
In order to achieve SIL3/Category 3 with this wiring, you must install a suitably qualified
sensor, for example, in accordance with IEC 60947.
Assignable Parameters for Use Case 2.3
Set the "Evaluation of the sensors" parameter to "1oo2 evaluation" and the "Type of sensor
interconnection" parameter to "2-channel nonequivalent" for the relevant input. Disable the
"Short-circuit test" parameter.
76
Wiring Diagram for F-DI Modules - Two One-Channel Sensors Connected
Nonequivalently Via Two Channels, Internal Sensor Supply
WARNING
ET 200pro Distributed I/O System - Fail-Safe Modules
Operating Instructions, 05/2007, A5E00394073-02