Purchase now: Allen Bradley 1747-M2 4K EEPROM Module
Purchase now: Atlantechdrives provides you the 1747-M2, an indispensable memory backup device designed exclusively for the legacy Allen Bradley SLC 500 automation family. Specifically targeting the Fixed Hardware «Brick» controllers (e.g., 1747-L20, L30, L40), as well as the modular SLC 5/01 (1747-L511) and SLC 5/02 (1747-L524) CPU processors, this small but mighty chip provides 4 Kilobytes (4K) of EEPROM (Electrically Erasable Programmable Read-Only Memory). In industrial environments, relying solely on a small lithium battery or an internal capacitor to retain your PLC’s RAM memory during power outages is a massive operational risk. The 1747-M2 allows you to «burn» a permanent, non-volatile copy of your finalized ladder logic program directly onto the silicon chip. If the PLC loses power for months and the internal battery dies, this module guarantees your machine’s logic is perfectly preserved.
Technical Specifications of the 1747-M2
The 1747-M2 utilizes EEPROM technology, meaning it does not require any external power source to retain its data. It mounts directly into the dedicated memory socket located on the printed circuit board of the host SLC processor.
- Part Number: 1747-M2
- Component Type: EEPROM Memory Backup Module
- Compatible Processors: SLC 500 Fixed Hardware, SLC 5/01, SLC 5/02
- Storage Capacity: 4K Words (Instructions and Data)
- Memory Technology: EEPROM (Non-volatile, battery-less retention)
- Primary Function: Permanent program storage and auto-recovery
Expert Tips: The Auto-Load Configuration
Simply plugging the 1747-M2 into the processor does not automatically protect your machine; you must configure the software. Expert Tip: Once your final program is burned to the EEPROM using RSLogix 500, you must configure the processor’s Status File (S:1) to dictate how it handles the memory module. The most critical setting for maintenance teams is setting the S:1/10 bit to 1 (Load Memory Module on Memory Error). With this bit set, if the machine is powered off over a long holiday weekend and the PLC battery dies (causing a RAM fault), the processor will automatically detect the RAM error on the next boot-up, silently copy the pristine 4K program from the 1747-M2 back into RAM, and enter RUN mode. This auto-recovery feature instantly restores the machine to a functional state, saving thousands of dollars in emergency engineering call-outs.
Installation Advice: Handling and Pin Protection
The 1747-M2 is a delicate, static-sensitive microchip with exposed metal pins. You must disconnect all 120V AC or 24V DC power from the SLC chassis before attempting installation. Use a grounded anti-static wrist strap. When inserting the EEPROM into the processor’s socket, ensure that the small semi-circular «notch» on the chip aligns perfectly with the matching notch printed on the processor’s circuit board. Press down gently and evenly. If inserted backward, applying power to the PLC will instantly and permanently destroy the EEPROM chip.
Frequently Asked Questions (FAQs)
Q: Will the 1747-M2 work in my SLC 5/03 or 5/04 processor?
A: No. The SLC 5/03, 5/04, and 5/05 processors require vastly more memory and utilize a different physical chip socket. For those processors, you must use a larger EEPROM module, such as the 1747-M13 (64K).
Q: Can I use this chip to quickly copy a program to multiple machines?
A: Yes! OEM machine builders frequently use the 1747-M2 as a physical «master copy.» You can insert the programmed chip into a new, unprogrammed PLC, configure it to load from EEPROM, and instantly replicate the machine’s logic without needing to connect a laptop.
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To ensure non-volatile backup for your PLC programs, this memory module is the direct companion for the 1747-L532 processor.
