Allen-Bradley 1756-L72S ControlLogix Controller

The Allen-Bradley 1756-L72S GuardLogix Controller is a Series B GuardLogix 5570 control module designed for integrated safety-enabled industrial automation. It ships with 4 MB RAM and 2 MB nonvolatile memory, providing ample program and data storage for complex control tasks, and uses the 1756-BATA 3V lithium battery to preserve memory during power loss. Built to endure harsh plant environments, it operates from 0 to 60 °C (32 to 140 °F) and dissipates about 2.5 W of power. As part of Rockwell Automation's Studio 5000 and RSLogix 5000 ecosystems, the L72S is configured in Studio 5000 (version 21 or later) or RSLogix 5000 (version 20 or later), enabling safety-rated logic and safety integration where required. The 1756-L72S is a controller within the GuardLogix 5570 family and is commonly used for safety-enabled automation applications, including scalable control architectures that combine logic with safety I/O and safety-certified peripherals. Series B designation indicates updated hardware revision and compatibility with other 5570-series controllers, backplanes and modules, supporting Rockwell's integrated Control/GuardLogix solutions for centralized control with built-in safety features.