Achievable Safety Classes with F-I/O
5.2 Safety Functions for Achieving Safety Classes for F-I/O with Inputs
Safety Engineering in SIMATIC S7
5-8
System Manual, 04/2006, A5E00109529-05
Example: Two Redundant Sensors Connected via One Channel to Two F-DIs (High Availability;
SIL3/Category 4)
The following figure presents the wiring diagram for 1oo2 sensor evaluation of the sensors
connected to two SM 326, DI 24 ☓ 24 VDC modules. The sensor is supplied by the F-I/O.
This wiring enables SIL2/Category 4 and high availability to be achieved. SIL3/Category 4
can only be achieved if a suitably-qualified sensor is used.
/
0
',
',
9V
/
0
',
',
9V
60
',['&9
60
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OHIW&KDQQHOVWR
ULJKW&KDQQHOVWR
OHIW&KDQQHOVWR
ULJKW&KDQQHOVWR
0HDVXUHPHQWRIWKHVDPHSURFHVV
GDWDZLWKPHFKDQLFDOO\LQVXODWHG
VHQVRUV
Figure 5-8
Example: Wiring Diagram for Two Redundant Single-channel Sensors Connected via
One Channel to Two F-DIs (1oo2, High Availability)
1oo2 Evaluation for F-I/O with Analog Inputs
The 1oo2 evaluation for F-I/O with analog inputs can be performed with one or more
sensors. The sensors are connected to the F-I/O via one or two channels.
