Mitsubishi QJ71MB91 User Manual

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5.2 Master Function
5.2.1 Automatic communication function
5
FUNCTIONS
5.2 Master Function
This section explains the functions of the QJ71MB91 acting as a MODBUS master.
5.2.1 Automatic communication function
The automatic communication function is a function by which device read/write request
messages are automatically issued from the QJ71MB91 to the MODBUS compatible
slave devices.
Figure 5.1 Communication using the automatic communication function
4
2
5
3
1
6
7
(FG)
(FG)
RS-232
/485
RS-422
CH2
RDB
RDA
SDB
SG
SDA
CH1
QJ71MB91
RUN
RD
NEU.
SD
NEU.
RD
SD
CH1
CH2
ERR.
Read
Auto Refresh
R
R
RS-485
Read
Read
Write
Programmable controller CPU
Device memory
QJ71MB91 (Master function)
Buffer memory
R
Automatically issues the
MODBUS device read/write
request message to Slave.
R
MODBUS slave device
(Third party remote I/O,
etc)
Holding register
MODBUS slave device
(Third party sensor, etc)
Holding register
MODBUS slave device
(Third party
programmable controller)
Holding register

Mitsubishi QJ71MB91 Specifications

General

Brand	Mitsubishi
Model	QJ71MB91
Category	Controller
Language	English