Siemens S7-300 Installation And Operating Manual page 92

Digital modules
8.3 SM 326; DI 24 x DC 24V
To achieve SIL3/Cat.4/PLe using this wiring, you must use a suitably qualified sensor.
Wiring scheme for application 5 with two-channel connection of one two-channel sensor
One two-channel sensor is connected via two channels to each of two
digital module for each process signal (1oo2 evaluation). The sensors can also be connected
to an external sensor supply.
Figure 8-16
To achieve SIL3/Cat.4/PLe using this wiring, you must use a suitably qualified sensor.
Wiring scheme for application 5 with two-channel connection of two single-channel sensors
Two single-channel sensors are connected via two channels to each of two
of the digital module for each process signal (1oo2 evaluation structure). The sensors can
also be connected to an external sensor supply.
Figure 8-17
92
WARNING
Wiring scheme of the SM 326; DI 24 x DC 24V for application 5 – one two-channel
sensor two-channel connection
WARNING
Wiring scheme of the SM 326; DI 24 x DC 24V for application 5 – two single-channel
sensors two-channel connection
Installation and Operating Manual, 01/2010, A5E00085586-10
opposite inputs
of the
opposite inputs
Fail-safe signal modules