GE IC695CMM002 RX3i Serial Communications Module (2 Ports)

Description

The GE IC695CMM002 (now under Emerson as part of the PACSystems RX3i family, with revisions like -DD or others in listings) solves the common challenge of adding robust, isolated serial connectivity to RX3i controllers without external gateways or protocol converters. In industrial automation setups — especially legacy integrations with older instrumentation, HMIs, barcode readers, scales, printers, or third-party devices — the base RX3i CPU may lack sufficient native serial ports or require non-isolated interfaces that risk noise or ground loop issues. GE IC695CMM002 provides two fully independent, isolated RS-232/RS-485 ports in a single slot, supporting flexible protocols like Modbus RTU Master/Slave and Serial Read/Write for direct device polling, data exchange, or custom messaging. It’s particularly essential in process control environments needing high reliability for multi-drop networks, remote telemetry, or protocol bridging — ensuring deterministic communications, noise immunity, and easy diagnostics while preserving backplane bandwidth for other I/O or motion modules.

GE IC695CMM002 plugs into any available slot on an RX3i universal backplane, acting as a dedicated serial communications coprocessor that handles protocol execution independently of the main CPU. Each port is software-configurable (via Proficy Machine Edition) for RS-232 (full/half-duplex) or RS-485 (2-wire/4-wire multi-drop), with baud rates from 1200 to 115200 bps, parity options, and framing. It supports Modbus RTU Master (up to 240 slaves) or Slave modes for polling or responding to external masters, plus generic Serial Read/Write for ASCII/binary custom protocols. Data exchange occurs via COMMREQ instructions or mapped %R/%G registers, with up to 1000 words per transaction and buffering for efficiency. Isolation (1500 V port-to-port and port-to-logic) protects against field transients, while LEDs indicate port activity, errors, and module health. Positioned in the communications layer of the RX3i stack, GE IC695CMM002 complements Ethernet options, enabling hybrid networks and up to six modules per CPU for expanded serial connectivity without scan time impact.

Selecting GE IC695CMM002 delivers flexible, protected serial expansion that integrates legacy devices seamlessly into RX3i systems. The dual isolated ports and Modbus support enable direct multi-drop connections to field instruments or HMIs, reducing external hardware and wiring while the coprocessor design offloads protocol handling to avoid CPU scan delays. Comprehensive diagnostics — port LEDs, fault tables, and status bits — speed troubleshooting, and configurable framing/parity accommodates diverse equipment without custom ladder. In practice, GE IC695CMM002 supports reliable polling or messaging in noisy environments, with high noise immunity and error checking for consistent data integrity. Long-term, it extends RX3i usability cost-effectively, bridging older serial assets to modern controllers while ensuring critical system uptime in mixed-protocol applications.

GE IC695CMM002 is frequently deployed in manufacturing for serial interfacing with barcode scanners, weigh scales, or printers on production lines, where Modbus RTU polling formats data for PLC decisions. In utilities or water/wastewater facilities, it’s used to connect remote meters, analyzers, or RTUs in process control environments, maintaining stable multi-drop communications over extended distances. Oil & gas or chemical plants apply it for legacy transmitter integration or HMI links, valuing isolation and high reliability under EMI-heavy or hazardous conditions.

Related or alternative products in the Emerson PACSystems RX3i communications family include:

IC695CMM004 – 4-port version for higher serial density needs.

IC695ETM001 – Ethernet module (SRTP/Modbus TCP) as a primary network alternative or complement.

IC695CMU310 – RX3i CPU with embedded serial ports for basic needs without add-ons.

IC693CMM321 – Legacy Series 90-30 Ethernet module for migration reference.

IC695PNC001 – PROFINET Controller for modern Ethernet I/O expansion.

IC695CHS012 – 12-slot universal backplane to host GE IC695CMM002 and other modules.

IC200CMM020 – VersaMax serial module as a lower-cost alternative in distributed setups.

IC695ACC400 – RX3i accessories like cables for serial port connections.

Before installing GE IC695CMM002, confirm RX3i universal backplane compatibility (e.g., IC695CHS series) and slot availability with sufficient power (e.g., IC695PSA040). Power down if replacing, insert firmly, and connect field wiring to DB-9 or terminals (RS-232/RS-485 pinouts per manual; use shielded twisted-pair for RS-485). Use Proficy Machine Edition to configure ports (baud, parity, mode), map registers, and set COMMREQ logic — download hardware config. Ground shields properly and test with loopback or known devices during commissioning, verifying LEDs (port activity, faults) and data exchange.

Ongoing maintenance involves routine checks: monitor LEDs for power OK, port status, and errors. Inspect connectors annually for corrosion or loose fits, especially in humid/industrial areas. Use Proficy diagnostics to trend comm faults, timeouts, or CRC errors — address cabling or device issues early. Test Modbus/serial links yearly with a master/slave simulator. Firmware updates (if released) apply via Proficy, testing offline first. The single-slot design supports hot-swap in many cases — swap with spare, reconfigure, and validate communications without full shutdown.