Allen-Bradley 1756-L73 ControlLogix Processor Module

Allen-Bradley 1756-L73 ControlLogix Processor Module is a high-performance CPU for Rockwell Automation's ControlLogix system, part of the LOGIX5573 family. It provides 8 MB of user memory for programs and data and supports up to 128,000 I/O points across the backplane, enabling large, data-rich control schemes. The processor is designed for use with standard 1756 I/O modules and supports substantial digital and analog I/O configurations—up to 4,000 analog I/O and 128,000 digital I/O in typical configurations. It dissipates about 2.5 W and has a continuous isolation rating around 30 V, with standard internal logic at 5 V. The 1756-L73 is available in Series B variants and conformal-coated forms such as L73K for harsher environments. In practical terms, this processor handles complex automation tasks, batch control, and manufacturing-line applications, coordinating module communications via the ControlLogix backplane and enabling firmware updates within Rockwell's ControlLogix ecosystem.