GE IC693PCM311J -640K Coprocessor Module

The GE IC693PCM311J is a Programmable Coprocessor Module (PCM) designed for the GE Fanuc Series 90-30 PLC platform. It extends the processing and communication capabilities of the PLC by providing dedicated memory, serial communication interfaces, and support for application programming using MegaBasic and C languages. It is mainly used in applications requiring advanced data handling, protocol conversion, device communication, and customized control functions.

Core Functions

• Provides an additional processing environment independent from the main PLC CPU.
• Executes user-developed programs using MegaBasic or C programming languages.
• Handles communication tasks between PLC systems and external intelligent devices.
• Supports industrial communication protocols including:
  • Modbus RTU
  • GE Fanuc CCM (CIMPLICITY Control Message protocol)
• Functions as an RTU master for remote communication applications.
• Performs data collection, formatting, logging, and protocol management tasks.

Technical Specifications

Design Features

Dedicated Coprocessing Capability

Unlike standard PLC CPU modules, the IC693PCM311J provides a separate execution environment, allowing communication-intensive or calculation-heavy tasks to run without significantly affecting PLC scan performance.

Large Memory Capacity

The integrated 640 KB battery-backed RAM provides sufficient storage for application programs, configuration data, and operational information.

Flexible Serial Communication

The dual serial ports allow connection with:

• Operator terminals
• Barcode readers
• Printers
• Intelligent instruments
• SCADA systems
• Remote terminal units (RTUs)

Industrial Programming Support

Support for MegaBasic and C programming gives engineers flexibility for developing customized automation functions.

Hardware Composition

The module consists of:

• Processor subsystem
  Dedicated coprocessor hardware for executing user applications.
• Memory system
  Battery-backed RAM for program storage and data retention.
• Serial communication section
  Two independent communication channels for external device integration.
• Front-panel interface
  Includes status LEDs for module operation and communication monitoring.
• Battery backup circuit
  Maintains RAM contents during power loss periods.

Typical Applications

The IC693PCM311J is commonly applied in:

• Industrial automation control systems
• Factory data acquisition systems
• SCADA communication networks
• Energy and utility monitoring systems
• Process control equipment
• Machine communication gateways
• Legacy GE Fanuc Series 90-30 installations

Typical tasks include:

• Collecting field device data
• Managing communication protocols
• Performing custom calculations
• Connecting PLC systems with third-party equipment

Maintenance Considerations

• Check and replace the lithium backup battery periodically to prevent loss of stored programs and data.
• Verify serial communication parameters such as baud rate, parity, and protocol configuration.
• Confirm compatibility with the installed Series 90-30 CPU and rack configuration.
• Avoid installation in unsupported embedded CPU systems or expansion/remote racks.
• Maintain backup copies of MegaBasic/C application programs before module replacement.

Overall Evaluation

The GE IC693PCM311J 640K Programmable Coprocessor Module is a specialized communication and application-processing module for GE Fanuc Series 90-30 PLC systems. With its large memory capacity, dual serial interfaces, and programmable environment, it provides a practical solution for extending PLC functionality in complex automation systems. Although it belongs to an older PLC generation, it remains valuable in legacy industrial installations where reliable communication expansion and customized processing are required.