GE IC695CMM004 RX3i Series Serial communication module

As a serial communication module in the RX3i industrial control system, the core function of IC695CMM004 is to establish a serial data transmission channel between the CPU and external devices, enabling bidirectional data exchange. Its working principle is based on a three-layer architecture of "Protocol Conversion + Electrical Adaptation + Isolation Protection", with the specific logic as follows:

• Physical Interface Support: Connects to external devices via RS-232, RS-485/422 interfaces, with interface type selectable via software configuration.

• RS-232: Supports hardware handshake (RTS/CTS), suitable for short-distance, point-to-point communication.

• RS-485/422: Supports multi-node, long-distance communication (up to ~1200 meters for RS-485), featuring differential signal transmission for strong anti-interference capability.

• Electrical Signal Conversion: Integrates level conversion circuits (e.g., RS-232 to TTL) internally to ensure signal compatibility between different devices.

• Port Isolation: Electrical isolation (typically ≥1500V) between serial ports and between ports and the backplane via optoelectronic or magnetic isolation technology, preventing external interference from affecting the control system and avoiding signal crosstalk between ports.

• Fault Protection: Built-in overvoltage and overcurrent protection circuits to prevent interface damage from transient voltages (e.g., lightning strikes, device startups/shutdowns).

• LED Indicators: Feedback module status (e.g., power, communication link, faults) via different colors and blinking frequencies for on-site debugging and maintenance.

• Hardware Monitoring Circuit: Continuously monitors internal components (e.g., RAM, Flash). Sends fault reports to the CPU via the backplane upon detecting issues (e.g., watchdog timeout, memory errors).

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• Multi-Protocol Support: Each port can be independently configured as MODBUS Master/Slave, DNP3 Master/Slave, CCM Slave, or Serial I/O protocol. Note: If any port is configured as DNP3, all other ports must also use DNP3 (protocol compatibility restriction).

• Protocol Parsing Logic:

• MODBUS Master: Actively sends query commands and parses register data returned by slaves.

• MODBUS Slave: Monitors master commands and responds to register read/write requests.

• DNP3 Protocol: Primarily for power systems, supporting real-time data acquisition and control command ，with features like event triggering and data priority management.

1. CPU sends a communication task (e.g., read slave registers) to the module via the backplane.   2. Module encapsulates the command frame per the configured protocol (MODBUS), adding slave address, function code, register address, etc.   3. Selects the corresponding port (RS-232/485) and sends data at the set baud rate (e.g., 9600bps).   4. Receives the response frame from the slave, parses the data, and verifies it (e.g., CRC check).   5. Transmits valid data to the CPU via the backplane to complete a communication cycle.

• Adjustable baud rates from 1200bps to 115.2Kbps, with software-configurable data bits (5–8), stop bits (1–2), and parity (none/odd/even) to match communication parameters of different devices.

• Installation: Only compatible with the RX3i universal backplane, communicating with the CPU via backplane buses (e.g., PCI or dedicated industrial buses) for control command and data transmission.

• Firmware Requirement: Requires RX3i CPU firmware version ≥3.83 to ensure hardware-protocol driver compatibility.

• Configures module parameters (e.g., protocol type, port attributes, communication settings) using Machine Edition software (v5.6 SIM 6 or higher). The software generates corresponding drivers for the CPU to recognize the module and schedule communication tasks.

• Meets standards such as CE, UL/CUL 508, ATEX, ensuring safety in industrial environments (e.g., explosion-proof, EMI resistance).

• Temperature: -20°C to 60°C (operating), -40°C to 85°C (storage).

• Humidity: 5%–95% non-condensing.

• Withstands industrial vibrations and shocks for long-term stable operation.

• Manufacturing Production Lines: As a MODBUS Master, connects to multiple sensors and actuators (e.g., inverters, PLC slaves) via RS-485 for real-time data acquisition and control command ，enabling long-distance, multi-node communication.

• Power Monitoring Systems: Configured as DNP3 Master, communicates with RTUs (Remote Terminal Units) in substations to collect voltage/current data and receive control commands from dispatch centers, ensuring real-time monitoring and scheduling of power systems.