Mitsubishi QJ71MB91, User Manual

Page: 185 / 372

7
PARAMETER SETTING
7.3 MODBUS(R) Device Assignment Parameter
7.3.3 QJ71MB91 buffer memory assignment
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7.3.3 QJ71MB91 buffer memory assignment
The QJ71MB91 can assign the MODBUS devices to the QJ71MB91 buffer memory.
By this assignment of the QJ71MB91 buffer memory to the MODBUS device, access to
the MODBUS devices will not be affected by sequence scans.
This allows the QJ71MB91 to respond faster to the master.
(1) To assign the QJ71MB91 buffer memory to the MODBUS device
(a) When using the MODBUS device assignment parameter
When setting the MODBUS device assignment parameter, set F000
H
for the
device code.( Section 7.3.1 (2))
(b) When using the default assignment parameter
Use any of the MODBUS device, 422529 to 426624.
(
Section 7.3.1 (3))
(2) Assignment range of MODBUS devices
The following QJ71MB91 buffer memory addresses can be assigned to the
MODBUS devices.
Table7.9 Usable buffer memory
Buffer memory
Address
Size Name Automatic refresh
5000
H
to 5FFF
H
(20480 to 24575)
4096 User free area Setting allowed