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8. COMMUNICATIONS USING DEDICATED PROTOCOLS
MELSEC-A
(b) Using the QR command (AnACPU dedicated command)
-
AJ71 CZ4
/
Designation of device
Batch read (word)
range to be read
command
dwisepoinb)
Character area
A
1 point of the device uses 4 characters.
Character area
B
'Ornputer
POINT
To designate the device range, the following conditions must be met:
I
1
5
number of device points
5
64 (32 for a bit device)
E h P C
No.
HlL
(Head device number)
+
[(number of device points** )
-
1 1
5
maximum
device number
**
("number of device points" x 16 for a bit device)
Example
1:
To read data at 32 points from X40 to
X5F
in station
"5".
(Message wait time is 0 msec)
I
I
I
No.
HlL
1
1
2
1
/
3
1 .
4
A
I
B
I
\
C
I
D
X X X
X X X X X X X
X X X X
4
4
4
. . . . . . . . . . . . . . . . . . . .
4
4
4
4
5
5
5
. . . . . . . . . . . . .. . . . . . .
5
5
5
5
F E D
3 2 1 O F E D
3
2
1
0
i
POINTI
The QR command is used for word unit designation. The designation for
32 points of devices from X40 to
X5F
is "02" ( " I " for 16 points).
Computer
M-ge
waiftime
/
Check sum is calculated
within this range
.
AJ71 C24
L , f
Check sum is calculated
within this range
E
N
o
m~
I
I
I
I
I
I
Head device
Bcharscten)
I I I I I I
A
c
K
a ~ , x ~ r s + s . $ l ~ , a .
0 5 F F
s
T
x
02"
I
Numberd
dwiu, point9
(2charackn
OleuuleFimal)
H I
L
m .
O 5 F F 1 2 3
J O ~ ~ l * . 4 6 . , 4 6 ~
I
Therefore,
a
l-word data is expressed
Sum
in 4 digits (hexadecimal).
A
' 2 . "
H l L
o
~
~
~
o
~
o
x
o
o
o
o
~
o
o
s . , n . , n . , m . , > o . , w . , J o .
4 1 A B C D
3 1 ~ , 1 2 r , ~ , ~ ~ ~ 4 1 ~ , 1 2 w , 1 ~ , l ~ r
I
S t
NO.
H I L
I
PC
No.
HIL
2
a., a.
E
T
x
01"
A Z
u.,u-
C 8
ll&
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