Why the IC693CMM311N Still Earns Its Slot
Legacy Series 90-30 racks keep production lines running long after the original install date. When a communications coprocessor drops offline, the whole cell loses visibility. The IC693CMM311N from GE Fanuc / GE Intelligent Platforms solves that problem with two independent serial ports and a dedicated Intel 80C186-based coprocessor that handles protocol traffic without loading the main CPU.
Emerson now owns the GE automation portfolio, and this N revision module remains a practical drop-in for existing 90-30 installations. If you maintain aging oil, gas, or process automation assets, this is the kind of spares when you need them part that keeps a shutdown from becoming a budget event.
Dual Ports, Four Protocols, One Module
The IC693CMM311N carries Port 1 as RS-232 and Port 2 configurable as RS-232, RS-422, or RS-485. That flexibility matters when one rack must talk to a local HMI on RS-232 while polling remote devices over a longer RS-485 run.
Supported protocols include CCM, Modbus RTU, SNP, and SNP-X. Baud rates span 300 to 19200 bps, which covers the majority of legacy field devices still in service. The coprocessor draws 400 mA at 5 VDC from the backplane, so verify your power budget before adding it to a fully loaded rack.
Integration Note
Wiring this module into a serial network may require external converters or connection modules, particularly when moving between RS-232 and RS-422/RS-485 segments. Confirm cables, converters, and pinouts with your supplier before commissioning.
Where This Module Fits
Oil and gas remote terminals. Modbus RTU over RS-485 lets the IC693CMM311N poll flow computers, tank gauges, and analyzers across a wide site. The second port can feed a local operator panel without interrupting the polling loop.
Water and wastewater pump stations. SNP and SNP-X support programming and data exchange with GE operator interfaces, which suits distributed lift stations that still rely on 90-30 hardware.
Legacy line upgrades. When a plant replaces an HMI but keeps the existing PLC rack, this coprocessor bridges old serial devices to the new supervisory layer, protecting the original capital investment.
Environmental and Physical Notes
The module operates from 0 to 60 °C and stores from -40 to +85 °C. Relative humidity of 5 to 95% non-condensing suits most control rooms and sheltered cabinets. The IP20 rating means the module belongs inside an enclosure, away from dust and moisture ingress. Supplier-reported weight is approximately 0.53 kg.
Selection Advice Before You Buy
Confirm three things: the rack has 400 mA of spare 5 VDC capacity, your field devices match one of the supported protocols, and your cable lengths suit the chosen electrical interface. Because this is a legacy module, please verify current lifecycle status and availability with Oil AutoTech before ordering. The team provides hands-on technical selection help and fast dispatch, worldwide.
Contact Oil AutoTech today for pricing and availability.
