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5.3 MELSECNET/H Module Access Function
5.3.5 Link data transfer processing time specifications
5
ACCESS VIA NETWORK MODULES
(b) Link scan and link device refresh
Link scans are NOT synchronized with link device refreshes of the C Controller
module.
Link device refreshes are performed in the link device refresh cycles set for the C
Controller module.
(2) How to calculate the transmission delay time
(a) Delay time in transmission within the same network
1) Cyclic transmission (periodic LB/LW/LX/LY communications)
The transmission delay time in B/W/Y communications is calculated with the
following.
• Link device refresh cycles of the sending and receiving side C Controller
modules
• Link device refresh times of the sending and receiving side C Controller
modules
• Scan time (excluding the link refresh time) of the programmable controller
CPU (receiving side)
• Link refresh time of the programmable controller CPU (receiving side)
• Link scan time
The formulas are as follows:
L
T : Link device refresh cycle of C Controller module (sending side)
L
R : Link device refresh cycle of C Controller module (receiving side)
T : Total link device refresh time of C Controller module (sending side)
*1
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R : Total link device refresh time of C Controller module (receiving side)
*1
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S
R : Scan time (excluding the link refresh time) of programmable controller
CPU (receiving side)
*2
R : Link refresh time of programmable controller CPU (receiving side)
*1,*2
LS : Link scan time
*2
Figure 5.32 Link scan and link device refresh
Link device
refresh
Link device
refresh
Link device
refresh
Link device
refresh
Link device
refresh
Link scan
Link device
refresh cycle
[Transmission delay time (TD1) of B/W/Y communications]
1) When a C Controller module (another CPU) receives data
(Until data are stored into internal link device buffer)
T
D1 = LT + T + (LS 1) + (SR+ R) 2 [ms]
T
D1 = LT + T + (LS 1) + R + LR [ms]
2) When a programmable controller CPU receives data
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