Siemens SIMATIC ET 200S Installation And Operating Manual page 123

Wiring Diagram for Application 2.2 - Connecting Two One-channel Sensors to Two Channels
Two channels of two 1-channel sensors are connected to two inputs of the F-module for
each process signal (1oo2 evaluation). The sensors can also be supplied via an external
sensor supply.
Figure 7-26
Warning
To achieve AK6/SIL3/Category 3 using this wiring, you must use a sensor qualified for this
class.
Assignable Parameters for Use Case 2.2
Set the parameter "evaluation of sensors" to "1oo2 evaluation" and the parameter "type of
sensor interconnection" to "2-channel equivalent" for the relevant input. Deactivate the
parameter "short-circuit test."
ET 200S Distributed I/O System - Fail-Safe Modules
Hardware Installation and Operating Manual, 07/2005, A5E00103686-04
7.5 4/8 F-DI VDC24V PROFIsafe Digital Electronic Module
Wiring Diagram EM 4/8 F-DI DC24V - Two channels of Two 1-Channel Sensors
Connected, Internal Sensor Power Supply
Fail-Safe Modules
7-63