10 - 10 10 - 10
MELSEC-Q
10 DEDICATED INSTRUCTIONS
REMARK
The MODBUS
R
/TCP frames used in communication with the slave in this sample
program are as shown below.
Request message format (Master (QJ71MT91) Slave)
(H)
(L)
(H)
(L)
(H)
(L)
(H)
(L)
(H)
(L)
(H)
(L)
Function
code
Function
code
(17
H
)
Read head holding
register number
(2AF7
H
)
Read points
n
(0064
H
)
Write head holding
register number
(01F3
H
)
Write points
m
(0020
H
)
Write device data
1
(W0000 value)
Write device data
m
(W001F value)
Number
of bytes
m 2
(0040
H
)
(Number of bytes m 2)
Data
Response message format (Slave Master (QJ71MT91))
(H)
(L)
(H)
(L)
Function code
Data
(Number of bytes n 2)
Function code
(17
H
)
Number of bytes
n 2
(C8
H
)
Read device data
1
(411000 value)
Read device data
n
(411099 value)
