Siemens Simatic S7-1500 Manual page 45

Wiring diagram – connecting two single-channel sensors non-equivalent
Two single-channel sensors are connected non-equivalent to two inputs of the F-module for
each process signal (1oo2 evaluation).
You can also supply one or both sensors by means of an external sensor supply.
The figure below shows an example of the pin assignment of the fail-safe digital input
module F-DI 16x24VDC with non-equivalent connection of two single-channel sensors.
①
Backplane bus interface
②
Microcontroller 1
Image 5-7 Two single-channel sensors connected non-equivalently, internal sensor supply (top) or external sensor
supply (bottom)
To achieve SIL3/Cat.4/PLe using this wiring, you must use a suitably qualified sensor.
Digital input module F-DI 16x24VDC (6ES7526-1BH00-0AB0)
Manual, 01/2016, A5E03858068-AA
WARNING
5.4 Application 3: Safety mode SIL3/Cat.4/PLe
③
Microcontroller 2
④
Reverse polarity protection
Applications of the F-I/O module
45