The Allen-Bradley 1747-M11 is an EEPROM (Electrically Erasable Programmable Read-Only Memory) module designed for the SLC 500 series of programmable logic controllers. This module provides 8K words of non-volatile memory, serving as a reliable solution for backing up user programs and data. It allows for easy program transfer between processors without requiring a programming terminal and ensures that the application program is retained even during a complete power loss or when the processor’s battery fails. The 1747-M11 is compatible with SLC 5/01, 5/02, 5/03, 5/04, and 5/05 processors, making it a versatile and essential component for maintaining system integrity and simplifying maintenance in various industrial automation applications.