5
- 3
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
Содержание QJ71MB91
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