Mitsubishi Electric MELSEC-QS Series Safety Application Manual page 159

APPENDICES
POINT
(a)+(b)
WDT
(SM)
Master
station
monitoring
Safety
timer start
master
station on
CC-Link
Ladder Ladder
Safety
CC-Link
Safety
Safety
remote
I/O station
on CC-Link
Safety
(Input side)
Input
signal
CC-Link
Safety
Safety
remote
I/O station
on CC-Link
Safety
(Output side)
(a) to (e) in the figure corresponds to (a) to (e) in
(1) If setting value of the safety data monitoring time is equal to or less than the
value gained by the calculation formula above, an error may occur even in
normal communication status.
If setting value of the safety data monitoring time is needlessly long, the time
taken for (c) in Table APPX.1 may lengthen in the case of a safety
programmable controller error, resulting in excessive delay of safety response
performance.
(2) The maximum value of safety response time is explained in this manual. For
this reason, WDT, the maximum value of SM (scan time), is used in
calculation formulas, instead of SM.
Use SM when calculating a normal value.
(3) When the safety CPU module detects CC-LINK DATA RECEPTION
TIMEOUT (error code: 8320 to 8322), increase the safety refresh monitoring
time and safety data monitoring time as needed.
(C)
(WDT n) m
LS
Master station
monitoring
timeout decision
Safety refresh
monitoring time
Ladder Ladder Ladder
Safety data monitoring time
Table APPX.1
.
Figure APPX.1 Timing chart
Appendix 1 Calculating Safety Response Time of CC-Link Safety
(WDT n) m
Master station
monitoring
timeout decision
Safety refresh
monitoring time
Ladder Ladder Ladder Ladder
(d)+(e)
Safety
Safety CC-Link Safety CC-Link Safety
power supply
CPU module master module master module
module
CC-Link Safety
Safety remote I/O Safety remote I/O
station on station on
CC-Link Safety CC-Link Safety
Safety input Safety output
signal signal
Emergency stop switch Safety relay
Output
signal
APPX
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