Mitsubishi Electric MELSEC-QS Series Safety Application Manual page 36

4
PRECAUTIONS FOR USE OF SAFETY
PROGRAMMABLE CONTROLLER
A1
B1
Input
C1
Emergency stop switch
Figure 4.4 Example when CC-Link IE Field Network are used (multiple output points)
4
4.1 Precautions for Designing Safety Application
- 6
(d) When using CC-Link IE Field Network between safety programmable controllers
(multiple output points)
PFD = (PFD of A1) + (PFD of B1) + (PFD of C1) + (PFD of D1)
+ (PFD of A2) + (PFD of B2) + (PFD of D2)
-5
= (4.10 10 + 8.75
-5
+ (4.10 10
-4
= (3.08 10 ) + (PFD of C1) + (PFD of D1) + (PFD of D2)
PFH = (PFH of A1) + (PFH of B1) + (PFH of C1) + (PFH of D1)
+ (PFH of A2) + (PFH of B2) + (PFH of D2)
-10
= (9.20 10
-10
+ (9.20 10
-8
= (1.18 10 ) + (PFH of C1) + (PFH of D1) + (PFH of D2)
Output
D1
Safety relay
-5 -5
10 ) + (2.57 10 ) + (PFD of C1) + (PFD of D1)
-5
+ 8.75 10 ) + (2.57 10
-9 -9
+ 3.85 10 ) + (1.15 10
-9
+ 3.85 10 ) + (1.15 10
B2
-5
) + (PFD of D2)
) + (PFH of C1) + (PFH of D1)
-9
) + (PFH of D2)
A2
Output
D2
Safety relay