Allen-Bradley 1766-MM1 MicroLogix 1400 384 KB Non-Volatile EEPROM Memory Module

Product Overview

The Allen-Bradley 1766-MM1​ is a dedicated 384 KB non-volatile memory module engineered exclusively for the MicroLogix 1400 programmable logic controller (PLC) platform from Rockwell Automation. The Allen-Bradley 1766-MM1​ installs directly into the dedicated memory module port located beneath the utility cover on the front panel of a MicroLogix 1400 controller, requiring no wiring, external power connection, or configuration beyond software setup in RSLogix 500 or RSLogix Micro. As a critical accessory for MicroLogix 1400 systems, the Allen-Bradley 1766-MM1​ provides a separately allocated, battery-independent storage medium for user programs, data files, DataLog records, and recipe configurations—distinct from the controller’s internal integrated memory.

The defining functional characteristic of the Allen-Bradley 1766-MM1​ is its role as a secure, portable backup and transport mechanism. The module stores one user program at a time along with associated data files, allowing maintenance technicians to transfer a validated “golden” program from one MicroLogix 1400 controller to another without the use of a personal computer or programming software. This capability is invaluable in distributed manufacturing operations where multiple identical machines must run the same control program, in remote installations where a programming terminal is not available, and in emergency replacement scenarios where a failed controller must be swapped and restored from the field-installed memory module. When paired with the automatic loading feature controlled by status bit S:1/11 (“Load Memory Module Always”), the Allen-Bradley 1766-MM1​ functions as a boot module: upon every power-up, the controller automatically overwrites its internal RAM with the program stored on the module, ensuring the machine always starts with the correct, authorized control strategy.

The Allen-Bradley 1766-MM1​ is built on EEPROM/Flash non-volatile memory technology, meaning it retains stored programs and data indefinitely without requiring any battery power. This fundamentally distinguishes the module from the controller’s internal battery-backed RAM, which is vulnerable to data loss when the replaceable RTC battery is depleted or disconnected. For plants operating in environments where battery monitoring may be inconsistent, the Allen-Bradley 1766-MM1​ provides an independent, battery-free layer of program security. The module supports write protection for both data files and the memory module contents themselves, preventing accidental overwrites during maintenance and safeguarding critical programs in safety-related applications such as press control.

It is important to understand that the Allen-Bradley 1766-MM1​ does not increase the controller’s integrated memory capacity. Rather, it provides a separately allocated 384 KB storage medium for backup, restore, transport, and auto-recovery operations. The module supports program compare functionality, allowing technicians to verify that the program stored on the module matches the program currently running in the controller. It also supports insertion and removal under power—when hot-swapped, the controller recognizes the Allen-Bradley 1766-MM1​ after the next complete power cycle.

The Allen-Bradley 1766-MM1​ is currently classified as an Active Mature product in the Rockwell Automation lifecycle, carries a standard one-year warranty, and is manufactured in Singapore. The module is compatible with six MicroLogix 1400 controller variants: 1766-L32AWA, 1766-L32AWAA, 1766-L32BWA, 1766-L32BWAA, 1766-L32BXB, and 1766-L32BXBA. It carries cULus, CE, C-Tick, and Australian RCM certifications, and is rated for operation in ambient temperatures from -20°C to +60°C.

Technical Specifications