Write To Plc And Read From Plc - Mitsubishi Electric Q26UD(E)HCPU User Manual

15.3.1

Write to PLC and Read from PLC

(1) Write to PLC
If data cannot be written from the programming tool to the CPU module, check the following items.
When the High Performance model QCPU, Process CPU, or
Redundant CPU are used, the DIP switch SW1 is on.
The data is password-protected.
The write-target memory card or SD memory card is write-
protected.
The write-target memory card or SD memory card has not
been formatted.
The size of data to be written is larger than the memory
capacity.
If data cannot be written to the CPU module even after taking the above actions, the possible cause is a hardware
failure.
Please consult your local Mitsubishi representative.
(2) The program is rewritten unintentionally
The CPU module possibly performs boot operation. Perform Read from PLC with the programming tool and
check the boot file setting.
When boot operation is not performed, the possible cause is a hardware failure.
Please consult your local Mitsubishi representative.
For details on the boot operation, refer to the following.
User's manual (Function Explanation, Program Fundamentals) for the CPU module used
(3) Read from PLC
If data cannot be read from the CPU module to the programming tool, check if the target memory has been
correctly set.
After making sure that the target memory has been correctly set, reset the CPU module, and then read data from
the CPU module again.
When the RS-232 is used for connection, reduce transmission speed, and read data from the CPU module again.
If data cannot be read from the CPU module even after taking the above actions, the possible cause is a
hardware failure.
Please consult your local Mitsubishi representative.
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Check item Corrective action
Turn the DIP switch SW1 to OFF.
Unlock the password with the programming tool.
Cancel the protection.
Format the card.
• Secure sufficient free space in the memory.
• Organize the target memory.