Siemens S7-300 - Page 95

Digital modules
8.3 SM 326; DI 24 x DC 24V
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
95
WARNING
To achieve SIL3/Cat.4/PLe using this wiring, you must use a suitably qualified sensor.
Wiring scheme for application 6 with nonequivalent two-channel connection of two redundant
nonequivalent sensors
Two redundant nonequivalent sensors are required per process signal. One nonequivalent
sensor is connected to each of two
opposite inputs of the digital module for each module
(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
/
0
',
',
9V
60
',['&9
60
',['&9


OHIW&KDQQHOVWR
ULJKWFKDQQHOVWR
$FTXLVLWLRQRIWKHVDPH
SURFHVVYDULDEOHXVLQJPHFKDQL
FDOO\
VHSDUDWHGVHQVRUV
7KHOHIWFKDQQHOVUHWXUQWKHXVHUVLJQDOV
DOWHUQDWLYHFRQQHFWLRQRIWZRVLQJOHFKDQQHOVVHQVRUV
OHIW&KDQQHOVWR
ULJKWFKDQQHOVWR
Figure 8-19 Wiring scheme of the SM 326; DI 24 x DC 24V for application 6 – two redundant,
nonequivalent sensors two-channel nonequivalent connection
WARNING
To achieve SIL3/Cat.4/PLe using this wiring, you must use a suitably qualified sensor.