Mitsubishi Electric MELSEC QS Series User Manual page 74

5
DATA LINK PROCESSING TIME AND STATION
STATUS AT ERROR OCCURRENCE
(2) Safety master station (RY)
5
- 17 5.2 Transmission Delay Time
5.2.3 Safety master station Remote device station
The following indicates the time from the moment a device of the safety CPU module
turns ON (or OFF) until the remote device station outputs ON (or OFF).
[Calculation formula]
[Normal value]
(a) Synchronous mode
SM n + LS + Remote device station processing time
• SM:Sequence scan time of safety CPU module
• LS :Link scan time (Refer to Section 5.1.)
• n :(LS/SM) value that is rounded up to the nearest whole number
(Example) When the sequence scan time of the safety CPU module is 20ms,
the link scan time is 3ms, and the remote device station processing
time is 20ms:
SM
= 20
= 43 [ms]
(b) Asynchronous mode
SM + LS + Remote device station processing time
• SM:Sequence scan time of safety CPU module
• LS :Link scan time (Refer to Section 5.1.)
(Example) When the sequence scan time of the safety CPU module is 20ms,
the link scan time is 3ms, and the remote device station processing
time is 20ms:
SM + LS + Remote device station processing time [ms]
= 20 + 3 + 20
= 43 [ms]
Remote device station (output/RWw)
n + LS + Remote device station processing time [ms]
1 + 3 + 20
*1
[ms]
*1
[ms]