Mitsubishi R04CPU MELSEC iQ-R PLC CPU Module Machine Control and Execution The Mitsubishi R04CPU is a MELSEC iQ-R PLC CPU with a 40K-step program capacity. It uses stored-program cyclic operation and processes LD instructions in 0.98 ns. Initial, scan, fixed-scan, event, and standby execution types support different control tasks. I/O operates in refresh mode. Direct access is also available through DX and DY addressing. Memory and Performance Specifications Parameter