Mitsubishi Electric QJ71LP21 Reference Manual page 84

3 SPECIFICATIONS
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(6) Transmission delay time formula
The transmission delay time is calculated based on the following system design
and conditions.
(System design, conditions)
1) CPU module:QO6HCPU
2) Total number of remote I/O stations: 8
3) Number of link devices: LX = LY = 1024 points, LB = LW = 0 point,
SB = SW = 512 points
4) Remote master station CPU module scan time: 1 ms
5) Communication speed: 10 Mbps
6) File register not used.
7) Transient transmission not used.
8) Remote master station mounts the network module to the main base unit.
9) All remote I/O stations only use the input/output module.
10) The link device per each remote I/O station is LX = LY = 128 points.
(a) Link refresh time (αm)
αm = KM1 + KM2
+ α
+ (network module cards –1)
E
= 0.13 + 0.41
/16 + 0 + (1 –1)
= 0.41 [ms]
(b) Link scan time (LS)
LS = KB + (0.45
(LW
16)} /16
+ {LXM R + LBM R + (LWM R
+ (T
= 4.0 + (0.45
+ {1024 + 0 + (0
+ {1024 + 0 + (0
+ (0
= 11.8 [ms]
(c) I/O refresh time
T = XK/16
RIOR
+ YZ/16
= 128/16
= 0.024 [ms]
(d) Cyclic transmission delay
Since Sm = 1 [ms],LS = 11.8 [ms], the Sm < LS formula is used.
1) Input transmission delay time (T
= (Sm + αm)
T
DX
= (1 + 0.41)
= 24.6 [ms]
2) Output transmission delay time (T
= (Sm + αm)
T
DY
= (1 + 0.41)
= 23.6 [ms]
{LB + LX + LY + SB + (LW
-3
10 {0 + 1024 + 1024 + 512 + (0
total number of remote I/O stations) + {LX + LY + LB +
16)} /8 0.001 + KR + {LYM R + LBM R + (LWM R
0.0003
0.001)
8) + {1024 + 1024 + 0 + (0
16)} /16
16)} /16
0.001)
0.0016 + XZ/16
0.0022
0.0016 + 0 + 128/16
round up [LS/(Sm + αm)]
[11.8/(1 + 0.41)]
round up [LS/(Sm + αm)] + LS + T
[11.8/(1 + 0.41)] + 11.8 + 0.024
16) + (SW
16) + (512
16)} /16 0.0003
16)} /8
0.0003
0.0003
0.0024 + YK/16 0.0014
0.0014 + 0
)]
DX
2 + Sm + T
2 + 1 + 0.024
)]
DY
MELSEC-Q
16)} /16
16)}
0.001 + 3.9
RIOR
RIOR
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