FANUCIC697CPU731XSeries 90-70 Single-Slot CPU Module, 12 MHz 80C186, 32 KB Battery-Backed Memory, 512 I/O

Product Description

What this part is

This is a GE Fanuc Series 90-70 CPU module, catalogue number IC697CPU731 — the processor that scans and solves the ladder program in a Series 90-70 rack. It is a CPU-tier module, not an I/O card and not an expansion or communications board: it holds the user program and the reference tables, and the rack does nothing without it. It occupies a single slot, which is the practical selling point of this catalogue number — larger 90-70 CPUs eat two or more slots and cost you I/O capacity.

Decoding the catalogue number

IC697 — the GE Fanuc Series 90-70 family prefix.
CPU — the module class: central processing unit. Compare CMM (communications), MDL (I/O), ALG (analog), BEM (bus expansion) — the three letters are the whole functional identity.
731 — the CPU model within the range: 12 MHz, 32 KB, single slot.
A trailing letter as in IC697CPU731X, -H or -L is the firmware / hardware revision level. It is not a different model, but on a 90-70 the revision matters because the programming software must support the firmware in the CPU — read the section below before you buy.

Firmware and revision: read this before you buy:
Series 90-70 CPUs pair with a specific band of programming-software versions (Logicmaster 90-70 under MS-DOS, later VersaPro and Proficy Machine Edition under Windows), and the connection is made either over the SNP serial port or over Ethernet through a separate Ethernet interface module. If your existing rack runs a documented firmware level, note the revision letter on the module you are replacing: a CPU at a revision your software cannot store to will connect, report, and then refuse the download. This is the single most common reason a physically-good 90-70 CPU appears faulty on arrival.

Published specifications

Processor: 80C186 at 12 MHz
User memory: 32 KB battery-backed CMOS, with the program/data split user-configurable
Scan performance: 0.4 µs per Boolean instruction
Discrete I/O: up to 512 points, in any mix of inputs and outputs
Slot usage: single slot in a Series 90-70 rack
Programming: Logicmaster 90-70 (MS-DOS) or Windows-based software, via the SNP serial port or over Ethernet TCP/IP through an Ethernet interface module

What these specs mean in practice

32 KB is the constraint that decides whether this CPU suits your application, not the clock speed. A machine-control ladder with a few hundred rungs and modest data tables fits comfortably; a recipe-driven process with large arrays, string handling or extensive analog scaling will not, and no amount of tuning gets round it — you move up the CPU range instead. The 0.4 µs Boolean figure is what makes the module perfectly adequate for fast discrete logic despite its age: scan time on a 512-point discrete machine is dominated by I/O service, not by the processor. And because the user memory is battery-backed CMOS, the battery is a maintenance item, not an accessory: a flat battery on a stored or unpowered CPU means the program is gone.

Quantity and configuration

One CPU module ships. No rack or baseplate, no power supply, no battery, no I/O modules, no Ethernet or communications module, no programming cable and no software or licence are included. Plan on a fresh lithium battery and a full program download before commissioning.

Installation and setup notes

Power down and lock out the rack before inserting or removing the module — 90-70 CPUs are not hot-swappable, and a live insertion risks both the card and the backplane. Seat the module fully and secure the faceplate screws so the backplane connector stays engaged under vibration. Fit a fresh battery before you download, then verify the retained program after a deliberate power cycle rather than trusting the first successful download. Keep the CPU in the leftmost CPU slot per the rack’s slot rules, and check the rack’s 5 V budget if you are adding modules at the same time.

Interchange guidance

Searched as IC697CPU731, IC697CPU731X, IC697-CPU731, IC697 CPU731, IC697CPU-731 and Series 90-70 CPU 731. Revision-suffixed builds — IC697CPU731H, IC697CPU731L and IC697CPU731X — are the same module at different firmware/hardware revisions and are carried as cross-references, with the revision level being the difference that matters for software compatibility. Higher CPUs in the same rack family (IC697CPU771, IC697CPU781, IC697CPU788) offer more memory and speed but are not slot-for-slot equivalents and need their own firmware and software support. Brand and support history for search reach: GE Series 90-70, GE Fanuc Automation, GE Intelligent Platforms, now Emerson — the platform’s migration path is Emerson’s PACSystems RX7i and RX3i, which are a project rather than a swap. The record’s brand field read “Fanuc”; this is a GE Fanuc catalogue part (IC697 is a GE Fanuc prefix, not a Fanuc CNC prefix) and has been corrected.