Table of Contents
Advertisement
8. COMMNICATIONS USING DEDICATED PROTOCOLS
MELSEC-A
8.1 0.3
Reading data from the special-function module buffer memory (ACPU common command)
esignation Methodl
St. No.
: Station number
Designation in protocol
1
is shown below.
POINT
(1) To designate the byte length, the following condition must be met:
Special function module buffer
2 characters
memory read command
(hexadecimal)
Character area A
I
Number of characters
=
+
I
1
5
byte length
5
128
omputer
(2) With some special function modules, 2 or 3 bytes are used to
express the data. Therefore, designate the byte length by referring
to the manuals for each individual module.
-
esignation Example1
E
N
Q
To read the datafrom buffer memory address07FOH to 07F3H (4 bytes) of the special-functiol
module (module number 13H) loaded at I10 numbers 120 to 13F in station number "0'
(Message wait time is 0 msec)
H l L H l L
I
I I I I
H
I
L
H
I
L
H I L
I
I
I
I
I
I
I
I
HIL HIL
Check sum is calculated
within this range
A
J71 C24
Designation of the special function
module buffer memory addres
range to be read from
I
ik,
Character area B
s
z
I
cE
wail time
Check sum is calculated
within this range
I
Byte length
(2 characters
T R
I
I
I
I
Head address
I 5
characters
(hexadecimal))
St.
NO.
HIL
A
c
K
m6
AJ7i C24
T
X
This indicates that special function
module
I10
allocation is 120 to 13F
I
Special func-
tion module
numb.r
PC
NO.
HIL
r
o F
M K , ~ .
l-word data uses 2 characters.
S
m
F F
%.,%
X
~ a , , ~ ~ ~ I n ~ , u I I ~ ~ , a a ~ . n , , u ,
O O F F
Memory data
be read
tmm
I
I
I
,
8
,
UILIHILI
i n l L
Indicates that:
The contents of buffer memory address 007FOH is 12H
The contents of buffer memory address 007FiH is 78H
The contents of buffer memory address 007F2H is 43H
The contents of buffer memory address 007F3H is 65H
,
t
E
1 2 ' 7 8 1 4 3 1 5 5 T 9 3
I
I
I
:
csmk
code
H I L
Advertisement
Table of Contents
