GE IC693CMM311L: Communications Control Module

This communications module enables data exchange between PLCs and external devices. It handles serial messaging for the Series 90-30 automation platform. The GE IC693CMM311L bridges the gap between factory floor equipment and control systems. You can configure this unit for point-to-point or multi-drop networks.

Technical Parameters Overview

Communication Port Architecture

Furthermore, the GE IC693CMM311L provides two independent serial interfaces. One RS232 port supports local connections to programming terminals. A second RS485 port enables multi-drop networking with up to 31 devices. Each port operates with individually selectable baud rates. Therefore, you can match communication speeds to different device capabilities.

Internal Processing and Memory Management

A 16-bit processor manages all communication tasks for this module. This processor includes 64 KB of available RAM buffer space. The buffer temporarily stores messages before the CPU reads them. Four capacitors provide 1,180 µF of distributed energy storage. That storage maintains active communication during momentary power sags. Consequently, the GE IC693CMM311L prevents data loss on unstable power feeds.

Component Layout and Signal Isolation

Moreover, 148 discrete components occupy two separate circuit boards. The main board contains the processor, memory, and power regulation. A secondary board hosts the RS232 and RS485 transceiver circuits. Optical isolators provide 1000 VDC separation between ports and backplane. This isolation eliminates ground loop currents between connected devices. The GE IC693CMM311L also includes electrostatic discharge protection on both ports.

Protocol Support and Configuration Options

For broad compatibility, this module supports three industrial protocols. Modbus RTU connects to thousands of third-party controllers and instruments. SNP protocol enables direct communication with GE HMI panels. CCM protocol supports custom peer-to-peer messaging between multiple PLCs. You can assign a different protocol to each port independently. As a result, one module simultaneously talks to diverse equipment brands.

Backplane Interface and System Integration

The rear edge connector fits into any Series 90-30 I/O slot. This connection carries power, data, and interrupt signals to the backplane. The GE IC693CMM311L draws only 220 mA from the 5 VDC supply. A hardware watchdog circuit resets the processor automatically upon lockup. You can place this module anywhere in the rack without restrictions. For example, position it beside the CPU for minimal response latency.