Mitsubishi QJ71MT91 User Manual

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MELSEC-Q
5 FUNCTIONS
(4) Automatic communication function buffer areas
(a) Automatic communication function buffer areas
The automatic communication function uses the following buffer memory
areas.
Name Application Buffer Memory Address
Automatic communication function
buffer input area
Stores data read from the
slave
1000
H
to 1FFF
H
Automatic communication function
buffer output area
Stores data to be written
to the slave
3000
H
to 3FFF
H
(b) Transfer direction of automatic communication function buffer
input/output area
The following shows the transfer directions of data stored into the buffer
memory by the automatic communication function.
1) Transfer direction in automatic communication function
buffer input area
When receiving a response message from the slave, the QJ71MT91
writes data to the automatic communication function buffer input area
in descending order of the addresses in 1 word (16 bits) unit.
2) Transfer direction in automatic communication function
buffer output area
When sending a request message to the slave, the QJ71MT91 creates
it by reading data from the automatic communication function buffer
output area in descending order of the addresses in 1 word (16 bits)
unit.
Ethernet
MODBUS /TCP slave device
R
Buffer memory
Automatic
communication
function buffer
input area
(1000
H to 1FFF H )
QJ71MT91
side receive
data write
direction
Programmable
controller CPU
side read direction
Programmable
controller CPU
side write direction
Automatic
communication
function buffer
output area
(3000
H to 3FFF H )
QJ71MT91
side send
data read
direction
QJ71MT91 (Master function)

Mitsubishi QJ71MT91 Specifications

General

Brand	Mitsubishi
Model	QJ71MT91
Category	Controller
Language	English