Mitsubishi Electric Melsec QJ71LP21 Reference Manual page 91

3 SPECIFICATIONS
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(d) Link refresh time
1) Basic model QCPU, High Performance model QCPU, Process CPU,
Redundant CPU, Universal model QCPU
The link refresh time (the time delay of the END processing time in the
CPU module) is obtained by the equation below using the following
variables:
• Number of assignment points of the link device
• Transfer to the file registers (R, ZR), extended data register (D), and
extended link register (W) on the memory card
• Inter-link data transfer
[Link refresh time]
α , α = KM1 + KM2
T R
LB + LX + LY
α = KM3
E
α = KM4 + KM5
L

: Link refresh time (sending station)
T

: Link refresh time (receiving station)
R
LB : Total points of link relays (LB) refreshed by the
corresponding station
LW : Total points of link registers (LW) refreshed by the
corresponding station
LX : Total points of link inputs (LX) refreshed by the
corresponding station
LY : Total points of link outputs (LY) refreshed by the
corresponding station
SB : Number of points of the link special relay (SB)
SW : Number of points of the link special register (SW)

: Transfer time of the file registers (R, ZR), extended data register (D), and
E
extended link register (W) on the memory card

: Inter-link data transfer time
L
KM1, KM2, KM3, KM4, KM5 : Constant
1: Total link device points that are within the range set in Refresh
parameters and that are set in Network range assignment.
Note that points assigned to reserved stations are excluded.
2: Add this value only when data is refreshed to the file register on the
memory card.
Do not add this value when data is refreshed to the file register on the
standard RAM and the extended SRAM cassette.
3: Add this value only when the inter-link data transfer function is used.
For Universal model QCPUs, the calculation method for the data link
transfer time varies.
The calculation method is shown in REMARKS.
LB + LX + LY + SB
16
+ LW [ms]
16
LB
+ LW [ms]
16
1
1
1
1
3
MELSEC-Q
+ LW + SW + α + α
E
Refer to Section
3.3.3.
2
[ms]
L
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