Allen-Bradley 1756-L55M16 ControlLogix Processor Module

The Allen-Bradley 1756-L55M16 ControlLogix Processor Module is a Series 2 CPU for Rockwell Automation's ControlLogix (Logix5000) platform, designed to run complex control logic in mid-to-large industrial automation applications. It ships with 7.5 MB of memory via the integrated 1756-M16 memory board, enabling substantial program and data storage and faster execution compared to earlier L55 configurations. As a processor module, it sits in a 1756 rack and communicates through the backplane with I/O, network, and motion modules, and is rated to support up to 128,000 I/O points depending on the chosen I/O modules and system configuration. The L55M16 designation indicates a base L55 controller paired with the M16 memory expansion, making it suitable for applications requiring larger firmware, data, and tag storage, such as automated production lines, packaging systems, and material handling. This module typically runs Rockwell Automation software compatible with ControlLogix controllers (RSLogix/Studio 5000), and is used when higher memory capacity and processing capability are essential for complex control schemes and Add-On Instructions.