IC693CMM321 Fanuc IC693CMM321 PLC Module

GE Fanuc IC693CMM321 | Series 90-30 Ethernet TCP/IP Interface Module — 10Mbps / SRTP / Modbus TCP/IP / 16 Servers / Discontinued

Adding Ethernet to the Series 90-30 — Client and Server in One Module

The IC693CMM321 is the Ethernet TCP/IP interface module for GE Fanuc's Series 90-30 PLC. It gives any Series 90-30 system an Ethernet LAN connection, enabling communication with host computers, SCADA systems, and other Ethernet-equipped PLCs on the same network — capabilities that the standard Series 90-30 CPU serial ports alone cannot provide.

The module operates in two communication roles simultaneously. As a server, it responds to requests from host computers and SCADA clients, serving PLC register and I/O data over SRTP (Service Request Transfer Protocol) or Modbus TCP/IP. Up to 16 server connections can be active simultaneously, allowing multiple supervisory systems or data clients to read and write PLC data concurrently. As a client, the IC693CMM321 initiates connections to other Ethernet-equipped devices from the PLC ladder programme using the COMMREQ function block — enabling PLC-to-PLC data exchange over Ethernet without a host computer intermediary.

The network connection uses an AAUI port with an external transceiver — this is 10Mbps 10Base-T or 10Base-2 Ethernet through a standard AAUI transceiver, not a direct RJ-45 connection. The external transceiver must be ordered and connected separately.

Key Specifications

CPU Firmware Compatibility

Full IC693CMM321 functionality requires Series 90-30 CPU firmware version 6.50 or higher. PLCs running CPU firmware versions 5.03 to 6.04 can use the module, but Ethernet operation is limited to a single SRTP server connection rather than the full 16. Verify the installed CPU firmware version against this requirement before deploying the module in a system running older CPU firmware.

Restart Button Functions

The front-panel restart button on the IC693CMM321 provides four functions:

1. Restart — reloads module firmware from flash and reconnects to the network
2. LED test — verifies all indicator LEDs illuminate correctly
3. Restart and Reload — forces a configuration reload from the CPU
4. Restart and Enter Maintenance Utility — enables firmware update and diagnostic mode

The button is inaccessible when the module's front door is closed.

FAQ

Q1: What is SRTP and why does it matter for Series 90-30 communication?

SRTP (Service Request Transfer Protocol) is GE Fanuc's proprietary TCP/IP application protocol for PLC communication. It allows host computers, SCADA systems, and other GE Fanuc PLCs to read and write PLC memory (registers, I/O, bits) over standard Ethernet. The IC693CMM321 acts as an SRTP server — any host running GE Fanuc's Host Communication Toolkit can connect and exchange data with the PLC over Ethernet.

Q2: Does the IC693CMM321 support Ethernet Global Data (EGD)?

No. The IC693CMM321 does not support Ethernet Global Data, which is GE Fanuc's high-speed peer-to-peer data sharing protocol used in later Ethernet modules (such as IC693CPU364 with built-in Ethernet). The IC693CMM321 supports SRTP and Modbus TCP/IP only. For EGD capability, a later Series 90-30 CPU with integrated Ethernet is required.

Q3: Why does the module use an AAUI port instead of a direct RJ-45 connection?

The IC693CMM321 was designed for the 10Mbps Ethernet generation that used AUI (Attachment Unit Interface) or AAUI (Apple Attachment Unit Interface) connectors with external transceivers before RJ-45 10Base-T became the universal standard. To connect to a modern RJ-45 switch or hub, an AAUI-to-10Base-T transceiver must be connected to the AAUI port. This is a normal requirement for this module generation, not a defect.

Q4: Can two IC693CMM321 modules be installed in the same Series 90-30 system?

Yes. Up to two IC693CMM321 modules can be installed in any Series 90-30 baseplate simultaneously. Each module operates independently with its own IP address and connection configuration. This provides two independent Ethernet interface channels for systems requiring higher connection capacity or network redundancy.

Q5: The IC693CMM321 is discontinued. Where is replacement stock sourced?

Through the GE Fanuc Series 90-30 aftermarket — industrial automation surplus dealers, GE Fanuc specialist parts suppliers, and tested exchange services. The IC693CMM321 appears in various suffix revisions (EE, JJ, etc.) — all revisions serve the same function. For new systems, GE's current Ethernet solutions for Series 90-30 should be confirmed with Emerson (the current GE Fanuc product line holder).