Batch Read Of Word Device (Wr Command) - Mitsubishi Electric MELSEC FX Series User Manual

FX communication
8.2

Batch Read of Word Device (WR command)

1 ) Command specification
Protocol format 1 is shown.
Batch read command (words)
Computer
Programmable
controller
Notes
• Specify the range and number of devices (16 bit words) so as to satisfy the following
conditions.
≤
- 1
- Head device No. + number of devices (number of devices
devices) -1
- When reading 32-bit devices (C200 to C255), the returned data is a double word.
Hence, the maximum number of devices is 32.
• The station number, PC (PLC) number, number of devices, and sum check code are
expressed in hexadecimal.
2 ) Command examples
a ) Example 1
To read 32 points of data from X040 to X077 at station No.5 (with message wait time set to
100 ms).
E
N
Q
Computer
05H
Programmable
controller
Notes
• Command WR uses word units. When reading 32 points, the number of devices is
specified by "02" (16 points (bits) per one word unit).
Character area A
Head device
(5 characters)
Specifies the range of
devices to be read.
≤
number of devices 64 (32 words in the case of bit devices) (13 words for FX
≤
max. device No.
0 5 F F W R 0 X 0 0 4 0
30H 35H 46H 46H 57H 52H 30H 58H 30H 30H 34H
The sum check is calculated
over this range
1
0 0 0 1 0 0
X X
0 0
5 5
7 2
One word device requires
four hexadecimal digits.
Therefore,one word is
Number of
devices
expressed using four
(2 characters,
characters.
hexadecimal)
0 2 4 8 The sum check is calculated
over this range
30H 30H 32H 34H 38H
S
T 0 5 F F 1 2 3 4
X
30H 35H 46H 46H 31H
02H
2 3 4
1 0 0 0 1 1 0 1 0 0
X X X X X X X X
0 0 0 0 0 0 0
5 5 4 4 4 4 4
1 0 7 3 2 1 0
Data of
the
specified
devices
Character area B
×
16 in the case of bit
E
A B C D T 0 8
X
32H 33H 34H 41H 42H 43H 44H 30H 38H
03H
A B C
1 0 1 0 1 0 1 1 1 1 0 0
X X X X
0 0 0 0 0
7 7 7 7 6
7 2 1 0 7
Commands 8
)
0N
8
A
C 0 5 F F
K
30H 35H 46H 46H
06H
D
1 1 0 1
X X X X
0 0 0 0
6 6 6 6
3 2 1 0
8-3