Precautions For Handling Files - Mitsubishi Q00JCPU User Manual

5
MEMORIES AND FILES HANDLED BY CPU MODULE

5.4.2 Precautions for handling files

(1) Power OFF (including reset) during file operation
When the PLC is powered OFF or the CPU module is reset during any file operation,
the files of the corresponding memory will be as described in Table5.9.
Basic model QCPU
High Performance model QCPU
Process CPU
Redundant CPU
POINT
(2) Simultaneous write from multiple GX Developers to the same file
The CPU module does not allow access from other GX Developers to the file being
written.
Also, it does not allow data to be written from other GX Developers to the file being
accessed.
When writing data from multiple GX Developers to the same file, start the processing
of next GX Developer after the processing of one GX Developer is completed.
(3) Simultaneous access from multiple GX Developers to different files
The CPU module allows simultaneous access from other GX Developers to a
maximum of 10 different files of the same CPU module.
Table5.9 File status at power OFF during file operation
CPU module
When the PLC is powered OFF during operation that transfers file(s), the data in
operation are held in the internal memory of the CPU module.
The held data are recovered at power-on.
To hold the internal memory data, battery backup is required.
5.4 File Operation by GX Developer and Handling Precautions
Memory status
The files of the corresponding memory may be corrupted.
The files of the corresponding memory are not corrupted.
(When the memory card is used, it is assumed that the PLC is
powered ON without removal of the memory card from the CPU
module in power OFF status.)
5.4.2 Precautions for handling files
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