Allen-Bradley 1756-M3 ControlLogix 2MB Expansion Memory Module

Product Overview

The 1756-M3 functions as a high-speed volatile expansion memory module specifically engineered for the Allen-Bradley ControlLogix 5555 (L55) controller series. It expands the user memory by 2 Megabytes, providing the necessary overhead for extensive ladder logic programs, complex tag databases, and data logging requirements. This module integrates directly onto the processor daughtercard slot, enabling immediate capacity upgrades without replacing the entire CPU. We supply this unit as 100% Brand New and factory-original, ensuring maximum data retention integrity and timing precision for your legacy automation infrastructure.

Technical Specifications

The 1756-M3 utilizes high-performance memory architecture to maintain rapid instruction execution speeds across the ControlLogix backplane.

Engineering Advantages

• Instant Logic Expansion: The 1756-M3 solves the common industrial bottleneck of "Memory Full" errors in aging L55 systems. By adding 2MB of dedicated space, it allows engineers to implement additional safety routines or communication rungs without optimizing or deleting existing critical code.

• High-Vibration Resilience: Designed for the plant floor, this module withstands shocks up to 30G and continuous vibration up to 2G. These specifications ensure the memory seat remains secure even when installed in cabinets mounted directly on high-impact machinery like stamping presses or industrial mixers.

• Thermal Stability: The module supports a full industrial operating range up to 60 °C. The open-style enclosure maximizes airflow from the chassis fans, preventing localized hot spots that could lead to data corruption or processor faults.

• Zero-Latency Integration: Because the 1756-M3 plugs directly into the processor's internal bus, it adds capacity without introducing the latency associated with remote storage or external communication links. The controller accesses the expanded memory at the same speed as the base onboard RAM.

FAQs

• Which processors support the 1756-M3 expansion module?

  This module primarily fits the 1756-L55 (ControlLogix 5555) series. Later models like the L6x, L7x, and L8x series use integrated non-volatile memory or different expansion architectures and do not utilize the M3 module.

• Is this module 100% Brand New or a refurbished "pull"?

  We guarantee this unit is 100% Brand New in original factory packaging. Unlike used memory modules that may have suffered electrostatic discharge (ESD) damage during improper handling, our new stock ensures clean electrical contacts and full component lifespan.

• Do I need to backup my program before installing the 1756-M3?

  Yes. Installing the memory module requires removing the processor from the chassis and potentially clearing existing memory. Always upload and save your project in RSLogix 5000 before hardware installation to prevent data loss.

• How do I verify the module is working after installation?

  Once installed and powered up, open the "Controller Properties" in your programming software. The "Memory" tab will reflect the total expanded capacity, confirming the processor has successfully initialized the 2MB expansion.