Series Six Combined Memory Module, 16K Logic / 8K Register, Battery-Backed CMOS RAM

What this part is:
GE Fanuc IC600LX624, a Combined Memory Module for the Series Six and Series Six Plus programmable controller. It is the board that holds the PLC’s user program and data — not a processor and not an I/O card. A single module carries all three memory functions at once: logic (user ladder program) memory, register memory, and internal memory.

Decoding the order code:
IC600 – GE Fanuc Series Six / Series Six Plus product familyLX – memory module (logic + register combined board)624 – the capacity variant: 16K words of logic memory, 8K words of register memoryTrailing letter (IC600LX624L, -A through -Z) – hardware revision level, not a different capacity

Published specifications:
Logic (user program) memory: 16K wordsRegister memory: 8K wordsInternal memory: included on the same boardMemory technology: CMOS static RAM, battery-backed, with on-board voltage-level detection circuitryBackup battery: lithium manganese dioxide, on the main circuit boardPower required from the rack CPU power supply: +5 V DC at 1.5 A max, −12 V DC at 10 mA maxWord length: 16 bitsRack position: slot 4, immediately to the left of the Arithmetic Control moduleCompatible platforms: Series Six (Model 60, 600, 6000) and Series Six Plus

What these specs mean in practice:
Logic memory sizes the program you can load; register memory sizes the data the program can hold. 16K/8K is the mid-to-upper tier of the Series Six range, so this board suits a machine whose ladder has outgrown a smaller LX module. Scan time on Series Six runs roughly 0.8 ms per K of user memory, so a fuller program costs scan time — sizing memory up does not make the PLC faster.

One important compatibility limit: this module works in a Series Six Plus rack, but it does not provide parity checking when used there. A Series Six Plus system that requires memory parity needs the Series Six Plus combined memory board instead. In a plain Series Six (60/600/6000) that distinction does not arise.

Because the memory is CMOS RAM, the program lives only as long as the backup power holds. Typical loaded battery life on this platform is about a year, with 8 to 10 years shelf life unloaded.

What is included:
Circuit board only, as pictured. This listing does not include a rack or backplane, a CPU rack power supply, the Logic Control or Arithmetic Control modules, an I/O Control module, a Communications Control Module, a programmer or Logicmaster 6 software, a memory cartridge, or a fresh backup battery. Treat any battery present as expired and fit a new lithium cell before you rely on program retention. No cable or connector kit is supplied — the module seats directly on the rack backplane.

Installation and setup notes:
Use the extraction/insertion tool supplied with the CPU to seat or pull the board; the Series Six backplane connectors are not designed for hand insertion. This is a static-sensitive assembly — ground yourself before handling and keep it in antistatic packaging until fitted. Install a known-good battery, then load the program and verify register contents before returning the machine to production; a module fitted with a dead cell will appear to accept a program and lose it at the next power-down. Confirm the memory-protect setting matches your intent so the program cannot be overwritten in service.

Interchange guidance:
IC600LX624 interchanges across its own revision letters — IC600LX624A through IC600LX624Z are the same catalogue item at different hardware revisions. Other IC600LX numbers are different capacities, not equivalents: fitting a smaller LX board to a rack whose program needs 16K logic will not run that program. Related items on the same platform, sold separately, include the IC600CP624 19-inch 11-slot CPU rack, the IC600CB516/CB536 Communications Control Modules, and Series Six I/O boards in the IC600BF and IC600YB ranges. Also searched as IC600-LX624, IC600 LX 624, LX624, and GE Series 6 memory board.