3 - 45 3 - 45
MELSEC-Q
3 SPECIFICATIONS
(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:Q06HCPU
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.
<Constants when a network module is mounted to the main base unit.>
Constant
CPU type
KM1
KM2
(
10
–3
)
KM3
( 10
–3
)
QnCPU 0.30 0.48 0.60
QnHCPU, QnPHCPU,
QnPRHCPU
0.13 0.41 0.53
(a) Link refresh time (αm)
αm = KM1 + KM2
{LB + LX + LY + SB + (LW 16) + (SW 16)} /16 + α
E
= 0.13 + 0.41 10
-3
{0 + 1024 + 1024 + 512 + (0 16) + (512 16)}
/16 + 0
= 0.41 [ms]
(b) Link scan time (LS)
LS = KB + (0.45
total number of remote I/O stations) + {LX + LY + LB +
(LW
16)} /8 0.001 + KR + {LYM R + LBM R + (LWM R
16)} /16 0.0003
+ {LXM
R + LBM R + (LWM R 16)} /16 0.0003
+ (T
0.001)
= 4.0 + (0.45
8) + {1024 + 1024 + 0 + (0 16)} /8 0.001 + 3.9
+ {1024 + 0 + (0
16)} /16 0.0003
+ {1024 + 0 + (0
16)} /16 0.0003
+ (0
0.001)
= 11.8 [ms]
(c) I/O refresh time
T
RIOR
= XK/16 0.0016 + XZ/16 0.0024 + YK/16 0.0014
+ YZ/16
0.0022
= 128/16
0.0016 + 0 + 128/16 0.0014 + 0
= 0.024 [ms]