Overview
The Allen-Bradley 1772-M8 core memory module is a foundational memory component for the PLC-2 processor family. With 8192 words of core memory capacity, this module delivers the reliable, non-volatile storage required for stable operation in legacy industrial automation environments. Designed for installation in the rightmost slot of the processor chassis, the 1772-M8 maintains data integrity even when power is removed, making it essential for critical control applications.
Key Features
- 8192-word capacity: Full core memory storage for PLC-2 processors
- Non-volatile memory: Data retention without external power
- Keyed connector design: Prevents improper installation and ensures correct alignment
- Diagnostic indicators: “STANDBY LOW” and “MEMORY FAULT” indicators for system monitoring
- Proven reliability: Decades of industrial use in manufacturing, automotive, and process control
Technical Specifications
- Memory Type: Core (magnetic core, non-volatile)
- Capacity: 8192 binary words
- Voltage Requirement: Battery-backed auxiliary power supply (specific voltage dependent on system configuration)
- Mounting Position: Rightmost slot in processor chassis
- Module Status Indicators: Standby Low (battery pack), Memory Fault (front edge)
- Connector Type: Keyed for correct orientation
Typical Applications
The 1772-M8 is well-suited for industrial environments requiring legacy PLC-2 support:
- Manufacturing equipment retrofits and upgrades
- Automotive production line control systems
- Food & beverage processing automation
- Textile machinery controllers
- Paper mill process control
- Packaging and assembly line systems
Compatibility & Replacements
The Allen-Bradley 1772-M8 is compatible with PLC-2/20 and PLC-2/30 processors. When installing this module, ensure power is removed and backup batteries are disconnected for safety. Related memory expansion options include the 1772-MS8 (8K memory segment for expansion modules) and 1772-ME8 (8K RAM memory module). For larger capacity requirements, the 1772-M16 provides 16K words. Given the legacy nature of PLC-2 systems, maintaining compatible spare memory modules is critical for minimizing downtime in established production environments.
