Mitsubishi Electric Q01UCPU User Manual page 46

(1) Precautions for handling files
(a) Power-off or reset during file operation
If the CPU module is powered off or is reset during file operation, files in each memory remain as is. (To hold
files in the memory card or SD memory card used, do not remove the card during power-off. Power off and on
the CPU module with the card being inserted.)
When the programmable controller is powered off during an operation in which a file is moved, 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.
(b) Simultaneous write from multiple programming tools to the same file
While data are being written to a file using a programming tool, another programming tool cannot access to the
file until the writing ends. Also, a file is being accessed by a programming tool, another programming tool
cannot write data to the file until the access ends. To write data to the same file from multiple programming
tools, wait until the current processing ends and perform the processing one at a time.
(c) Simultaneous write from multiple programming tools to different files
Up to 10 programming tools can simultaneously access to different files in a CPU module.
(d) Access to the SD memory card
Accessing the SD memory card by using the SP.FREAD or SP.FWRITE instruction may cause the scan time to
increase as the number of files stored in the SD memory card increases.
44