Mitsubishi Electric QD77MS User Manual page 804

[3] Precautions during control
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
Setting item
Flash ROM write
[Cd.1]
request
: Refer to Section 5.7 "List of control data" for details on the setting details.
(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 writing 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.
(1) Execution data backup (writing to the flash ROM/internal memory
(nonvolatile)) is carried out using the dedicated instruction "ZP.PFWRT".
(Refer to Chapter 15 "Dedicated Instructions" for details.)
(2) Refer to Section 7.2 "Data transmission process" for the data transmission
processing at the backup of the execution data.
(3) Execution data backup can also be 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
value
1 Set "1: Requests write access to flash ROM.".
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 details
14 - 8
Chapter 14 Common Functions
Buffer memory address
QD77MS2
QD77MS16
QD77MS4
1900 5900