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MELSEC-Q
4 MODBUS
R
STANDARD FUNCTIONS
4.3.8 Write multiple registers (FC: 16)
Writes values to multiple holding registers.
Number of accessible devices with one message
1 to 123 points
(1) Request message format (Master Slave)
Data
(H)
(L)
(H)
(L)
Function code
Function code
Device data
1
(Number of bytes n 2)
(H)
(L)
Device data
n
(H)
(L)
(10
H
)
Head holding
register number
(0000
H
to FFFF
H
)
Write points
n*1
(0001
H
to 007B
H
)
(0001
H
to 00F6
H
)
Number
of bytes
n 2*1
1: The number of points specified as the write points must be matched with the
number of bytes.
(2) Response message format (Slave Master)
(When completed normally)
Head holding register number
Data
Write points
(H)
(L)
(H)
(L)
Function code
Function code
(10
H
)
(The value same as in the
request message is stored.)
(The value same as in the
request message is stored.)
(When completed with an error)
Data
Function code
Function code
(90
H
)
Exception
code*2
2: When completed with an error, the exception code and error code are stored
into the buffer memory.
Refer to Section 11.3 for the storage location, confirmation method and more
details.
