Table of Contents
Advertisement
8. COMMUNICATIONS USING DEDICATED PROTOCOLS
MELSEC-A
8.5
Transmission Sequence Timing Charts and Communications Time
(1)
To read data from the AlSCPU to the computer
("*" indicates that the message wait time has been set.)
Computer
D
I
I
I
I
I
I
t
Wait rTW)
,
T3
,
' ,
T4
1
I
" ~ 5 % ~ ~
is 0 if the message wait time is
Read
,
not set or message wait time is shorter than
i \
\
communications time with the PC CPU.
Sequence
H
END
Step
0
END
Step
0
END
Step
0
IREMARK]
For file register and parameter, an extra 1 scan plus TZ is required
(2)
To write data from the computer to the AlSCPU
("*" indicates that message wait time has been set.)
END
Step
0
END
Step
0
END
Step 0
Computer
c
- 1
As shown above, communications between the AlSJ71C24 and the A l S C P U is always made
after END. Therefore, the scan time is extended by the time used for communications.
Appendix 5 gives the communications time
E
N
0
, \ , I
Section 3.3.1 gives the number of points processed per communication after END
To
.
*Wait rTW)
.
'
Check of PC CPU
Data
\
RUNISTOP, etc
write
A
c
K
i\
This period is
0
if the mes-
sage wait time is not set
or
message wait time is shorter
than communications time
with the PC CPU.
1.
TI
,I,
T2
.:.
Ts
-.
1 '
Advertisement
Table of Contents
