This manual introduces the communication protocols of the H1U/H2U series PLC, including hardware and communication connections, communication protocol switching logic, serial port communication format settings, communication protocol descriptions, etc.
This manual provides detailed information for configuring and troubleshooting communication between the Huichuan H1U/H2U series PLC and external devices. It covers hardware wiring, protocol selection, serial communication settings, error codes, and the specifications of each supported protocol.
The document includes tables of protocol settings, error‑code listings, and MODBUS slave protocol details, helping users set up RS485/RS422 interfaces, select the appropriate communication mode, and interpret diagnostic messages. This manual is written in Chinese.
| COM0 interface | Standard RS485/RS422, 8‑pin socket |
|---|---|
| COM1 interface | RS485, terminal block |
| Supported baud rates for N:N protocol | 38400 bps (default) |
Error code 0000 indicates no abnormality.