GE-FanucIC693CPU331KSeries 90-30 Single-Slot CPU Module, 80188 10 MHz, 16K Program Memory, 512 Discrete In / 512 Discrete Out

Product Description

What this part is

This is a Series 90-30 single-slot CPU module — the processor that runs the ladder program in a GE Fanuc Series 90-30 programmable controller. It drops into the CPU slot of a 5-slot or 10-slot baseplate, scans the I/O modules across the backplane, executes user logic and holds the register and reference tables. Series 90-30 was one of the most widely installed small PLC platforms in North American industry, and the CPU is the one module in the rack that has no substitute from another family.

Decoding the order code

IC693: GE Fanuc Series 90-30 product line.

CPU: central processing unit module, as distinct from MDL discrete I/O, ALG analog, CMM communications and APU motion.

331: the specific CPU model, 80188 processor, 16K user program memory, single-slot form factor.

K: hardware revision letter. Revision letters in this family track internal component changes and are functionally interchangeable.

Also written IC693-CPU-331-K, IC693 CPU 331 K and IC693CPU331.

Published specifications

CPU type: single-slot CPU module.

Processor: 80188, 16-bit.

Processor speed: 10 MHz.

User program memory: 16K bytes maximum.

Typical scan rate: 0.4 ms per 1K of Boolean logic.

Discrete inputs %I: 512.

Discrete outputs %Q: 512.

Register memory %R: 2048 words.

Analog inputs %AI: 128 words.

Analog outputs %AQ: 64 words.

Discrete global memory %G: 1280 bits.

Internal coils %M: 1024 bits.

Temporary coils %T: 256 bits.

System status %S, %SA, %SB, %SC: 32 bits each, 128 bits total.

Baseplates per system: 5 maximum, one CPU baseplate plus up to four expansion and/or remote.

Backplane load: 350 mA from the +5 VDC supply.

Operating temperature: 0 to 60 °C ambient.

Maths: integer operations only, no floating-point hardware.

What these specs mean in practice

16K bytes of program space is the defining limit of this CPU. It is fixed, with no memory expansion option for a CPU331. An application beyond that capacity moves to a CPU340/341/350 class processor. For sequential machine control, conveyor and packaging logic, and most retrofit applications where the CPU331 was originally specified, 16K is ample; a scan of 0.4 ms per 1K of Boolean means even a full program scans in single-digit milliseconds.

Integer-only arithmetic is the other decisive spec. A program that uses floating-point maths function blocks will not execute on this CPU. Recipe handling, PID with scaled real values and temperature or flow computation in engineering units are the usual cases. Fixed-point scaling in integer registers is the standard approach and is how most CPU331 programs were originally written.

512 discrete in and 512 discrete out is a large I/O count for a five-baseplate system, so the reference table is rarely the constraint; slots and program memory are.

Quantity and configuration

CPU module only, sold as 1 piece.

Mounting data

The CPU331 installs in the leftmost CPU slot of the baseplate, adjacent to the power supply, and cannot be placed in a general I/O slot.

The serial port is SNP protocol over RS-485, for programming with Logicmaster 90-30, VersaPro or Proficy Machine Edition. A Hand Held Programmer also communicates with it.

Memory backup uses a lithium cell, GE Fanuc part IC693ACC301.

Interchange guidance

Search forms include IC693CPU331K, IC693CPU331, IC693-CPU-331-K and IC693 CPU 331 K. The CPU331 sits between the entry-level embedded CPUs and the CPU340-and-up processors, which are related models with different memory and features. Program capacity and instruction support differ across that boundary. Within the CPU331 designation, revision letters are the interchangeable dimension. Series 90-30 is discontinued and legacy-supported; surplus, reman and board-level repair are the supply channels.