Mitsubishi Electric MELSEC-Q Series User Manual page 718

[3] Precautions during control
(1) Data can only be written to the flash ROM when the positioning control is not
carried out (when the PLC READY signal [Y0] is OFF).
The warning "In PLC READY" (warning code: 111) will occur if executed
when the PLC READY signal [Y0] is ON.
(2) Writing to the flash ROM can be executed up to 100,000 times.
If writing to the flash ROM exceeds 100,000 times, the writing may become
impossible, and the error "Flash ROM write error" (error code: 801) will occur.
(3) After one power ON/PLC CPU reset operation, writing to the flash ROM
using a sequence program is limited to up to 25 times.
If the 26th writing is executed, the error "Flash ROM write number error"
(error code: 805) will occur. If this error occurs, carry out the error reset or
power OFF ON/PLC CPU reset operation again.
Refer to "[Md.19] Number of write accesses to flash ROM" of Section 5.1.9
"Types and roles of monitor data" for details.
Important
Do not turn the power ON/OFF or reset the PLC CPU during executing the flash
ROM writing. If the power is turned OFF or the PLC CPU module is reset to forcibly
end the process, the data backed up in the flash ROM/internal memory
(nonvolatile) will be lost.
[4] Execution data backup method
(1) Refer to Section 7.2 "Data transmission process" for the data transmission
processing at the backup of the execution data.
(2) Execution data backup is carried out by the writing of the data shown in the
table below to the buffer memory of Simple Motion module using the TO
command/intelligent function device.
The writing to the flash ROM/internal memory (nonvolatile) is executed at the
time point the data is written to the buffer memory of Simple Motion module.
Setting item
Flash ROM write
[Cd.1]
request
: Refer to Section 5.7 "List of control data" for details on the setting details.
When the writing to the flash ROM/internal memory (nonvolatile) is complete,
"0" will be set in "[Cd.1] Flash ROM write request" by the Simple Motion
module automatically.
Setting
Setting details
value
Set "1: Requests write access to flash
1
ROM.".
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Chapter 14 Common Functions
Buffer memory
address
5900