Mitsubishi QJ71MB91, User Manual

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- 23 7.3 MODBUS(R) Device Assignment Parameter
7.3.2 MODBUS(R) extended file register assignment to the programmable controller CPU file register
7
PARAMETER SETTING
7.3.2 MODBUS(R) extended file register assignment to the programmable
controller CPU file register
The MODBUS extended file register assignment to the programmable controller CPU is
fixed to the file register (ZR).
It is assigned to the file register (ZR) of the programmable controller CPU as shown below.
(1) Out-of-range read/write request
The QJ71MB91 sends an exception response if the master requests it to read from or
write to a nonexistent file register (ZR) of the programmable controller CPU on the
station where the QJ71MB91 is mounted.
(2) MODBUS extended file register size
The MODBUS extended file register size is dependant on the file register (ZR) size
set to the programmable controller CPU on the QJ71MB91-mounted station.
POINT
Even if the slave (QJ71MB91) receives Write File Record (FC:21) when the
programmable controller CPU’s file register (ZR) is read-only (for example, when
stored on a Flash card), it will issue a normal response.
In this case, however, the action for Write File Record is not performed.
To write to the extended file register, check that the programmable controller
CPU's file register (ZR) is writable or not in advance.
Remark
For the programmable controller CPU's file register (ZR), refer to the following
manual:
User's Manual (Function Explanation, Program Fundamentals) for the CPU
module used
Figure 7.9 Extended file register assignment
600000
609999
600000
609999
600000
609999
600000
604063
ZR0
ZR9999
ZR10000
ZR19999
ZR20000
ZR29999
ZR4180000
ZR4184063
ZR4179999
ZR30000
10000 File number 0
10000 File number 1
10000 File number 2
4064 File number 418
Programmable controller
CPU file register (ZR)
R MODBUS
extended file register