OVERVIEW

Official designation: Allen-Bradley 1764-MM1 (MicroLogix 1500, Memory Module)

Role/Application: Removable memory module that provides non-volatile 8KB EEPROM storage for user program and data file backup, allowing program transfer and automated recovery on compatible MicroLogix 1500 controllers.

KEY SPECS SUMMARY

Power: Not applicable, non-volatile EEPROM

Interfaces / Ports: Memory module slot (internal)

Indicators: Program compare status file S:2/9

Operating Temp: 0 to 55 degrees C

Platform / Compatibility: 1764-LSP, 1764-LRP processors

Limit: 8 Kbytes user program and data

Lifecycle: Discontinued/Obsolete (No Replacement)

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What is the primary memory type used in the 1764-MM1 module?

A: The module utilizes 8KB of EEPROM memory for non-volatile program and data retention.

Wiring & Installation:

Q: Can the memory module be removed or inserted into the controller while power is applied?

A: Yes, the 1764-MM1 module supports removal and insertion under power.

Troubleshooting & Compatibility:

Q: What system status bit indicates a difference between the controller program and the module program?

A: The status bit S:2/9 is used to indicate a program comparison fault between the CPU and the module.

Replacement & Upgrades:

Q: Are there official, direct replacement memory modules with higher capacity for the 1764-MM1?

A: The 1764-MM2 and 1764-MM3 modules offer 16KB of memory but the entire MicroLogix 1500 system is obsolete.