Siemens S7-300 - Page 91

Digital modules
8.3 SM 326; DI 24 x DC 24V
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
91
Wiring scheme for application 5 with two-channel nonequivalent connection of one nonequivalent
sensor
One nonequivalent sensor is connected via two channels nonequivalently to each of two
opposite inputs of the digital module for each process signal (1oo2 evaluation). The sensors
can also be connected to an external sensor supply. The left channels of the module return
the user signals, that is, these signals are available in the I/O area of inputs at the F-CPU if
no errors are detected.
/
0
',
',
9V
60
',['&9
OHIW&KDQQHOVWR
ULJKWFKDQQHOVWR
7KHOHIWFKDQQHOVUHWXUQWKHXVHUVLJQDOV
Figure 8-14 Wiring scheme of the SM 326; DI 24 x DC 24V for application 5 – one nonequivalent
sensor two-channel nonequivalent connection
WARNING
To achieve SIL3/Cat.4/PLe using this wiring, you must use a suitably qualified sensor.
Wiring scheme for application 5 with nonequivalent two-channel connection of two single-channel
sensors
Two single-channel sensors are connected via two channels nonequivalently to each of two
opposite inputs of the digital module for each process signal (1oo2 evaluation structure). The
sensors can also be connected to an external sensor supply. The left channels of the module
return the user signals, that is, these signals are available in the I/O area of inputs at the F-
CPU if no errors are detected.
/
0
',
9V
',
9V
60
',['&9
OHIW&KDQQHOVWR
ULJKWFKDQQHOVWR
7KHOHIWFKDQQHOVUHWXUQWKHXVHUVLJQDOV
$FTXLVLWLRQRIWKHVDPH
SURFHVVYDULDEOHXVLQJPHFKDQLFDOO\
VHSDUDWHGVHQVRUV
Figure 8-15 Wiring scheme of the SM 326; DI 24 x DC 24V for application 5 – two single-channel
sensors two-channel nonequivalent connection