Mitsubishi Electric MELSEC-Q00U(J)CPU User Manual page 108

(5) Precautions
(a) Storage location of parameters
• Store the parameter file set in the Boot file tab of the PLC parameter dialog box to the memory card or SD
memory card. If it is stored in the program memory or standard ROM, the CPU module ignores the
settings. (
• The CPU module operates using the parameters in the program memory, not those in the memory card or
SD memory card, if the following conditions are both met.
1) A parameter file exists in the program memory.
2) The parameter file in a memory card or SD memory card is not set for boot target in parameter.
(b) Online change during boot operation
If the program in the program memory is overwritten online while the boot operation is being performed, the
change is not reflected to the program in the memory card or SD memory card.
Write the same program file to the memory card or SD memory card.
(c) Maximum number of settable boot files
Set the maximum number of settable boot files in the Boot file tab of the PLC parameter dialog box so that it
may be the same with the number of files storable to the program memory.
However, the number of boot files decreases by one when:
• The parameter file (with boot settings) stored in the memory card or SD memory card is booted.
• A heading is set.
(d) Boot operation when the ATA card is used
When data are booted from the ATA card, the processing time of maximum 200ms may be required per 1K step
(4K bytes).
(e) When data in the program memory are changed after the CPU module is powered off
and then on or is reset
If the program memory data are changed after the sequence program is written to the program memory and the
CPU module is powered off and then on or is reset, a boot operation may be active.
While the BOOT LED on the front of the CPU module is on, the boot operation is active. Refer to Page 105,
Section 2.11 (4) and stop the boot operation.
(f) File size before and after the boot operation
The size unit of a file stored in each memory differs. (
Note that files transferred from the memory card or SD memory card to the program memory differ in size
before and after the transfer.
(g) Program written to the memory card or SD memory card
Set the programmable controller type (model name of the CPU module) for the program written to the memory
card (program set in the Boot file tab) and the model name of the CPU module to be booted to the same.
Set the type (model) of the CPU module that actually performs the boot operation to the program (with boot
settings) written to the memory card or SD memory card.
106
Page 42, Section 2.1.2)
Page 50, Section 2.1.3 (4))