GE IC693CMM311N Communications Coprocessor

The GE IC693CMM311N adds serial communication ports to Series 90-30 PLCs. This coprocessor module handles ASCII string processing and data conversion. You will find it in systems that need to talk to barcode readers or printers. It offloads communication tasks from the main CPU. Therefore, this module improves overall system performance.

This module measures 140 mm in height and 32 mm in width. Its depth reaches 130 mm for standard rack mounting. The unit weighs approximately 0.28 kilograms. It contains one 16-bit coprocessor with dedicated memory. Two independent RS-232/RS-485 serial ports provide connectivity. Additionally, you get eight status LEDs for port activity monitoring.

Key Technical Specifications

Parameter	Value
Manufacturer	GE Fanuc Automation
Model	IC693CMM311N
Product Type	Communications Coprocessor Module
Serial Ports	2 (software selectable)
Interfaces	RS-232 or RS-485
Baud Rate	300 to 115.2 kbps
Data Format	7 or 8 bits, 1 or 2 stop bits
Parity Options	None, even, odd
User Memory	32 KB RAM
Buffer Size	2048 bytes per port
Height	140 mm
Width	32 mm
Depth	130 mm
Weight	0.28 kg
Coprocessor	16-bit @ 20 MHz
Status LEDs	8 (TX, RX, OK, FAULT)
Energy Storage	≈ 150 µF (capacitive)
Power Consumption	200 mA @ 5 VDC
Operating Temperature	0°C to +60°C

Internal Architecture and Energy Storage

The GE IC693CMM311N stores minimal energy in its filter capacitors. Small electrolytic capacitors hold approximately 150 microfarads total. A dedicated 16-bit coprocessor runs at 20 MHz independently. This processor handles all serial protocol processing without CPU intervention. Two UART chips manage the physical serial transmission and reception. The module includes 32 KB of battery-backed RAM for user programs. This RAM stores send/receive buffers and configuration data. A watchdog timer resets the coprocessor if it freezes.

Connection Interfaces and Wiring Details

You will find two 9-pin D-sub connectors on the front panel. Port 1 uses DB9 male, while Port 2 uses DB9 male. Connect RS-232 devices using a standard straight-through cable. Connect RS-485 devices using twisted-pair wires across terminals. The GE IC693CMM311N automatically detects the selected protocol after configuration. Use shielded cable for RS-485 networks longer than 50 feet. Eight red and green LEDs show transmit, receive, and module status. A software-selectable termination resistor allows end-of-line RS-485 connections.

Configuration and Installation Steps

You slide this module into any I/O slot of the Series 90-30 rack. First, align the module with the upper and lower card guides. Then, push it firmly until the backplane connector seats securely. Secure the front panel with the retaining screw. Use the programming software to configure each serial port. Set the baud rate, data bits, and parity for each device. The GE IC693CMM311N stores this configuration in battery-backed memory. Write your communication logic using the COMMREQ instruction block. The module handles all ASCII send and receive operations automatically. Test both ports with actual devices before system startup.