Allen-Bradley 1756-M12 ControlLogix 750 K Memory Module

The Allen-Bradley 1756-M12 is a 750 KB expansion memory module designed specifically for first-generation ControlLogix controllers, primarily matching the 1756-L55 (Logix5555) series. Installed directly into the controller's internal expansion slot, it expands user memory capacity for data tags, sequential routines, and complex process control programs.

System Compatibility and Memory Expansion

The module provides 750 KB of non-volatile program and data storage. It integrates directly onto the host processor board, combining with the base controller to form full assemblies such as the 1756-L55M12.

The 1756-M12 is compatible with the entire 1756-L55 controller family, including base models paired with other expansion options (such as 1756-L55M13, 1756-L55M14, 1756-L55M16, 1756-L55M22, 1756-L55M23, and 1756-L55M24). This modular architecture enables facilities to upgrade or replace memory components without disposing of the core controller hardware.

Operational Requirements and Environment

The module installs inside the main controller unit housed within a standard 1756 ControlLogix chassis. It draws operating power from the backplane via the host controller, with typical 5.1 VDC backplane current requirements for the combined assembly.

Designed for industrial environments, the module supports standard operating ambient temperatures from 0 to 60 deg C (32 to 140 deg F) and relative humidity levels between 5% and 95% non-condensing. Its lightweight design adds approximately 0.06 kg (0.13 lbs) to the controller unit.

Technical Specifications

Frequently Asked Questions

Q: Which controller family uses the 1756-M12 expansion memory module? A: The 1756-M12 is designed specifically for Allen-Bradley ControlLogix 1756-L55 (Logix5555) controllers, forming complete assembly units like the 1756-L55M12.

Q: Can the 1756-M12 module be installed directly into a chassis slot? A: No, the 1756-M12 is an internal memory daughtercard that plugs directly into the host 1756-L55 controller board, not into a standard 1756 backplane slot.