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MELSEC-Q
10 DEDICATED INSTRUCTIONS
(1) Operation of program example
Ethernet
b15 b5 b3 b0
0000000000000001
b15 b5 b3 b0
1
QJ71MT91
(Master)
Mask write
(OR)
MODBUS /TCP
slave device
(192.1.0.2)
R
<OR mask value>
<Holding register 400003>
(2) Frames sent and received by MBREQ instruction
(a) Request message format (Master (QJ71MT91) Slave)
(H) (L) (H) (L) (H) (L)
(0008
H
)
16
H
00
H
02
H
00
H
00
H
00
H
08
H
Function code Data
7 bytes
Function code Target holding register number AND mask value OR mask value
Sending order
(b) Response message format
<When completed normally>
(H) (L) (H) (L) (H) (L)
16H 00H 02H 00H 00H 00H 08H
Function code Data
7 bytes
Function code Target holding register number AND mask value OR mask value
Receiving order
(0008H)
<When completed with an error>
96H
Function code Data
2 bytes
Function code Exception code*
Receiving order
*: Refer to Section 11.3.2 for details of the exception code.