Mitsubishi QJ71MB91 - 7.3 MODBUS(R) Device Assignment Parameter

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7.3 MODBUS(R) Device Assignment Parameter
7
PARAMETER SETTING
7.3 MODBUS(R) Device Assignment Parameter
Using MODBUS device assignment parameters, the MODBUS devices are correlated
with the programmable controller CPU device memory.
This allows direct access from the MODBUS compatible master device to the
programmable controller CPU device memory.
Figure 7.6 MODBUS device and programmable controller CPU device
D300
D299 400499
D300 400500
D301 400501
Device
R
R
Programmable
controller CPU
No sequence
program required
1234
H
QJ71MB91 (Slave function)
R
MODBUS device assignment parameter
Device memory
MODBUS device
Request message (Write 1234 H to
holding register 400500)
MODBUS
Master device
RS-232, RS-422 or RS-485