GE Fanuc IC693CPU331W CPU Module for Series 90‑30

The GE Fanuc IC693CPU331W is a central processing unit (CPU) module for the Series 90‑30 programmable logic controller platform. This module serves as the brain of the control system, executing user logic and managing data exchange between I/O modules. Powered by an 80188 processor running at 10 MHz, the CPU offers a balanced combination of processing power and efficiency for mid‑range automation applications. It features 32 KB of user memory (RAM) with battery backup, supports up to 1024 discrete I/O points, and includes integrated RS‑232 and RS‑485 serial ports for programming and communication. The module also includes a LAN interface for networking capabilities.

Technical Specifications

The IC693CPU331W is powered by a 5 V DC supply from the Series 90‑30 backplane, with a current consumption of 350 mA. The CPU uses an 80188 processor with a clock speed of 10 MHz. User program and data memory is 32 KB (battery-backed RAM). Scan rate: 0.22 ms per K of Boolean logic. Maximum I/O capacity: 1024 discrete I/O points. The CPU supports both local and remote I/O expansion racks. Integrated communication ports: RS-232 and RS-485 serial ports, and a LAN interface for networking. The CPU module includes a battery backup for memory and real-time clock retention. Programming language: Relay Ladder Logic. Diagnostic functions include LED status indicators, error logging, and built-in self-diagnostics. Dimensions: 130 mm (H) × 35 mm (W) × 120 mm (D). Weight: approx. 0.3 kg. Operating temperature: 0°C to 60°C. Storage: -40°C to 85°C. The CPU is compatible with all Series 90‑30 I/O modules and expansion racks.

Key Features

• 80188 processor at 10 MHz for reliable logic execution

• 32 KB battery-backed user memory

• Scan rate of 0.22 ms per K of Boolean logic

• Supports up to 1024 discrete I/O points

• Integrated RS-232 and RS-485 serial ports

• LAN interface for seamless network communication

• Expandable with local and remote I/O expansion racks

• Battery backup for memory and real-time clock

• LED status indicators for quick diagnostics

• Relay ladder logic programming

Memory and Performance

The 32 KB of user memory is shared between program storage and data memory. The battery backup (lithium battery) retains the program and data during power loss; the battery should be replaced every 3-5 years. The scan rate of 0.22 ms/K ensures adequate throughput for most medium‑scale control applications. The CPU is capable of handling both discrete and analog I/O control tasks. The 80188 processor, while modest by modern standards, is optimized for deterministic real‑time control and provides sufficient performance for the Series 90‑30 platform’s intended applications. The CPU supports relay ladder logic programming, offering a familiar environment for engineers accustomed to traditional PLC programming.

Communication and Networking

The IC693CPU331W features a LAN interface that allows seamless communication and networking capabilities, enabling the CPU module to connect and exchange data with other devices on the local area network. This interface facilitates integration into larger plant-wide control systems. Two serial ports (RS-232 and RS-485) are available for programming, HMI connection, and Modbus communication. The RS-485 port supports multi-drop configurations. The CPU communicates with I/O modules via the backplane bus; expansion racks are connected via dedicated cables and remote I/O processors. The built‑in self-diagnostics and error logging functions help reduce troubleshooting time.

Applications

The IC693CPU331W is used in industrial automation applications such as machine control, process control, discrete and analog I/O control, and factory automation. Typical industries include automotive manufacturing, material handling, packaging, water treatment, and general industrial equipment. The CPU is often found in legacy systems where the Series 90‑30 platform is still in service, serving as a reliable replacement or upgrade path. Its support for remote I/O expansion racks allows distributed control configurations, reducing field wiring costs.

Installation and Expansion

The IC693CPU331W mounts in the CPU slot (slot 1) of a Series 90‑30 rack (IC693CHSxxx). Connect the power supply module to the rack; the CPU draws 5 V DC from the backplane. Install I/O modules in subsequent slots. For remote I/O expansion, connect an expansion cable from the CPU to a remote rack equipped with a remote I/O processor module. The CPU supports both local and remote expansion configurations. Programming is performed using GE Fanuc Logicmaster or Proficy Machine Edition software via the RS-232 or RS-485 programming port. The LAN interface allows network‑based programming and monitoring.

Maintenance and Diagnostics

The CPU has a red and a green LED for status indication. A green RUN LED indicates the CPU is in run mode and executing the program. A red ERROR LED indicates a fault. The CPU includes a built‑in diagnostic function that logs errors in a diagnostic buffer. The battery status can be monitored via the programming software. To replace the battery, remove the front cover of the CPU and replace the CR2032 lithium battery with the CPU powered on to avoid memory loss. The CPU is fanless and relies on passive cooling, requiring adequate clearance in the cabinet.

Conclusion

The GE Fanuc IC693CPU331W CPU module provides a reliable, field‑proven control solution for Series 90‑30 PLC systems. Its 32 KB memory, 0.22 ms/K scan rate, and integrated LAN interface make it suitable for mid‑range industrial automation applications. As a legacy component, it is primarily used for maintaining existing Series 90‑30 installations.