MELSEC-Q Series CPU Error Code 430DH Technical Bulletin

This technical bulletin from Mitsubishi Electric describes actions to take when error code 430DH (incorrect request message reception error) occurs during normal SLMP (MC protocol) or MODBUS/TCP communication on specific High-speed Universal model QCPU and Universal model Process CPU modules. It provides a decision flow to determine if the system is affected, advises contacting a local Mitsubishi representative if so, and notes that the system can be temporarily restored by power cycling or resetting the CPU module.