The GE Fanuc IC693MDL655L is a Series 90-70 Serial Communication Coprocessor designed to provide flexible serial communication between a PLC system and external industrial devices. As a Revision Q version of the CMM711 family, it supports multiple communication protocols and two independent serial ports, making it useful for legacy automation systems that require reliable data exchange.

Protocol Support

One of the main advantages of this module is its multi-protocol design. It supports several communication methods used in Series 90 PLC installations.

• SNP/SNP-X: Master or slave operation
• CCM: Master, slave, or peer operation
• RTU Modbus: Slave operation

Hardware Specifications

Series 90-70 Integration

The module occupies one slot in a Series 90-70 rack or CPU baseplate. Its compact design allows it to be installed alongside other communication, CPU, and specialty modules within the same control platform.

Moreover, the module is designed to provide high-performance access to PLC memory through supported communication protocols. This capability makes it useful when external systems need to read or exchange control data with an existing Series 90-70 PLC.

The historical GE Fanuc documentation identifies the CMM711 specifically as the Series 90-70 communication coprocessor, while the corresponding CMM311 was intended for Series 90-30 systems. Therefore, system compatibility should be checked before selecting a replacement module.

Configuration and Diagnostics

Configuration is handled through compatible GE Fanuc programming and configuration software. Historical systems commonly used Logicmaster 90-70, while later environments included VersaPro and Proficy Machine Edition/Logic Developer PLC.

The front panel provides three status indicators:

• OK – Indicates module operating status.
• PORT 1 – Indicates activity on the first communication port.
• PORT 2 – Indicates activity on the second communication port.

In addition, a front-panel pushbutton allows communication activity to be reinitialized without removing the module from the rack. Consequently, technicians can use the indicators and restart function as basic troubleshooting tools.

Typical Applications

This communication coprocessor can be used in a variety of industrial automation environments where serial communication remains part of the control architecture.

Typical applications include:

• Series 90-70 PLC communication
• Machine control systems
• Factory automation
• PLC-to-device data exchange
• Modbus RTU integration
• Legacy SCADA communication
• HMI and operator interface connections
• Industrial serial networks
• Existing GE Fanuc control system maintenance

Furthermore, its support for several protocols allows one hardware platform to serve different communication requirements. This flexibility can be particularly useful when maintaining older production equipment where replacing the entire PLC architecture would be impractical.

Replacement Value

The IC697CMM711Q remains relevant for maintenance of established Series 90-70 installations that depend on serial communication. Its dedicated communication processor, two configurable serial ports, multi-protocol support, and single-slot form factor provide a practical interface for extending the service life of legacy control systems.

For replacement projects, however, the exact hardware revision and existing system configuration should always be verified before installation. Matching the communication protocol, electrical interface, firmware requirements, and external wiring is essential for reliable operation.