The Allen-Bradley 1756-L55M12 LOGIX5555 Processor is a ControlLogix CPU with on-board memory, delivering 750 KB of user memory and 208 KB of I/O memory for program and data storage in demanding automation applications. As the M12 integrated-memory variant of the L55 family, it represents the LOGIX5555 line of ControlLogix CPUs. Rockwell's documentation places 1756-L55M12 among the L55 family (along with L55M13, L55M14, etc.), and PSAs note the L55M12 series was part of the older ControlLogix lineup that has since been discontinued. Third-party catalogs corroborate the memory configuration for the L55M12 variant, listing 750 KB of user memory and 208 KB of I/O memory.
