IC697CPU780 | GE Fanuc Series 90-70 32-Bit 16MHz 512KB Floating Point CPU Module

Module Overview

The IC697CPU780 is a high-performance central processing unit for the GE Fanuc Series 90-70 PLC family. As a 32-bit controller, it is specifically designed to handle complex mathematical operations and large-scale industrial processes that require floating-point precision. This module resides on the VME-based Series 90-70 backplane, providing a robust logic engine capable of managing extensive I/O networks. While officially discontinued by the manufacturer, the IC697CPU780 remains a critical component for maintaining legacy high-end automation systems in power generation, water treatment, and heavy manufacturing.

Detailed Technical Specifications

The IC697CPU780 offers a significant step up from standard 16-bit controllers by providing a native 32-bit environment for both integer and real-number calculations.

• Microprocessor: 32-Bit 80386DX running at 16 MHz

• User Memory: 512 Kilobytes (Battery-backed RAM)

• Floating Point Math: Integrated 32-bit hardware support

• Discrete I/O Capacity: Up to 12,288 (12K) total Inputs and Outputs

• Analog I/O Capacity: Up to 8,192 (8K) Analog Inputs

• Register Memory: Configurable up to 32,768 words

• Scan Rate: 0.4 milliseconds per 1K of boolean logic

• Bus Architecture: VME64 compatible (Series 90-70 Standard)

• Status Indicators: 3 LEDs (Top: Module OK; Middle: Run; Bottom: Outputs Enabled)

• Physical Weight: 0.99 lbs (0.45 kg)

• Operating Temperature: 0°C to 60°C (32°F to 140°F)

System Configuration and Programming

The IC697CPU780 features a three-position keyswitch on the front faceplate, allowing maintenance personnel to toggle between "Run with Outputs Enabled," "Run with Outputs Disabled," and "Stop/Configuration" modes. Configuration and logic development are traditionally performed using Logicmaster 90-70 or Proficy Machine Edition. Because this CPU manages such a large I/O table (12K points), it is often paired with Genius Bus Controllers (GBC) or Ethernet modules to distribute control across wide physical distances.

Functional Benefits of the 90-70 Platform

Unlike the mid-range Series 90-30, the Series 90-70 (and the IC697CPU780 specifically) is built on an open VME standard. This allows the CPU to interface with a variety of third-party VME modules in addition to standard GE Fanuc I/O. The 32-bit architecture ensures that complex PID loops and scientific calculations are executed with minimal latency, providing the "Large PLC" performance required for plant-wide control.

Technical FAQ

How is the user program protected in the IC697CPU780?

The module uses a lithium battery located on the baseplate (rack) to maintain the 512KB of RAM. It is highly recommended to back up the program to the internal non-volatile Flash memory (if equipped) or an external storage device to prevent data loss during long-term power outages.

What is the maximum number of racks this CPU can support?

When used with the appropriate bus transmitter/receiver modules, the IC697CPU780 can support a local rack and up to seven expansion racks, fully utilizing its 12K I/O addressing space.

Can this CPU handle C programming?

Yes. The Series 90-70 architecture supports C-block execution, allowing developers to write complex algorithms in C and integrate them directly into the Ladder Logic scan.