5 DATA LINK PROCESSING TIME
(b) For writing
MB = [SM + LS + {(No. of writing points + 16)/72}
+ SL + LS × 3 + β + constant bps] × N [ms]
SM : Master station sequence scan time
SL : Local station sequence scan time
LS : Link scan time (Refer to section 5.2)
α : Send end internal processing time
LS
β
: Receive end internal processing time
LS
[Constant bps]
Transmission speed
156kbps
constant bps
N : No. of execution instructions simultaneously
1 : Raise the decimals to a unit
(Example) When master station sequence scan time is 10ms, local station sequence
scan time is 10ms, link scan time is 5ms, no. of writing points is 20 words,
transmission speed is 10Mbps, no. of execution instructions simultaneously
is 1
MB = [SM + LS + {(No. of writing points + 16)/72}
+ SL + LS × 3 + β + constant bps] × N
= [10 + 5 + {(20 + 16)/72}
= [10 + 5 +1 × 5 + 5 + 10 + 5 × 3 + 5 + 5 × 7] × 1
= 90 [ms]
625kbps
LS
LS × 2
1
× 5 + 5 + 10 + 5 × 3 + 5 + 5 × 7] × 1
5 - 17
MELSEC-A
1
× LS + α
2.5Mbps
5Mbps
LS × 4
LS × 6
1
× LS + α
10Mbps
LS × 7