Mitsubishi QJ71MT91 User Manual

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MELSEC-Q
1 OVERVIEW
1 OVERVIEW
This manual explains the specifications, functions, programming, troubleshooting, etc.
of the MELSEC-Q series QJ71MT91 MODBUS
R
/TCP interface module (hereafter
abbreviated to the QJ71MT91).
The QJ71MT91 is used to connect the MELSEC-Q series programmable controller to
a MODBUS
R
/TCP network.
MODBUS is a registered trademark of Schneider Electric SA.
1.1 Features
(1) Supporting master function of MODBUS
R
/TCP communication
The QJ71MT91 supports the master function of MODBUS
R
/TCP
communication, which is an open network system for factory automation, and it is
compatible with various MODBUS
R
/TCP slave devices (hereafter abbreviated to
the slaves) of other manufactures.
The master function supports the following two functions.
(a) Automatic communication function
By setting the automatic communication parameters, MODBUS
R
device
data can be automatically read from or written to the slaves at the specified
intervals using the QJ71MT91 buffer memory. (
1)
Data can be transferred between the QJ71MT91 buffer memory and
programmable controller CPU device memory by making the auto refresh
setting with the utility package (GX Configurator-MB) or accessing a
intelligent function module device with a sequence program.
Device memory
Auto refresh
Ethernet
Programmable
controller CPU
Buffer memory
Holding register
Holding register
100ms read
1000ms read
250ms read
QJ71MT91
(Master function
)
R
R
100ms write
R
Holding register
R
MODBUS /TCP slave device
(Third party sensor, etc.)
MODBUS /TCP slave device
(Third party programmable
controller)
MODBUS /TCP slave device
(Third party remote I/O, etc.)
MODBUS device read/write request
messages are issued to the slave
repeatedly at specified intervals.
1: The MODBUS
R
device indicates the device area of the slave where data can be read/written in
response to a request from the master.
1

Mitsubishi QJ71MT91 Specifications

General

Brand	Mitsubishi
Model	QJ71MT91
Category	Controller
Language	English