Key benefits Industrialgrade design with robust port protection for stable, reliable operation in harsh environments. Easy diagnostics with abundant LED status indicators that quickly reveal device health and activity. Flexible power options from terminal or DC header input (8–28 V DC) with reversepolarity protection. A wide range of interfaces: RS485, RS232 (DB9), and 10/100 Mbps Ethernet; available in an isolated version with 8channel serial ports and independent hardware isolation. Flexible configuration options and wide communication support for rapid deployment and easy integration with existing systems. Advanced Modbus capabilities with gateway support, multiple servers, and cloud/MQTT compatibility for scalable industrial IoT deployments. 1. Industrial design and interfaces Industrialized, stable, and reliable construction with level port protection. Abundant LED indicators for quick working status checks. Power supply options include terminal or DC header connection; wide input range 8–28 V DC with reverse connection protection. Interfaces include terminal RS485 and standard DB9 RS232. Isolated version provides 8channel serial ports with independent hardware isolation for safety and noise immunity. Ethernet interface supports 10/100 Mbps. 2. Configuration and connectivity Configuration via a dedicated configuration tool and AT commands. Baud rates from 2400 to 115200 bps; parity options include odd, even, and none. Configurable DNS (domain name resolution) service. Timeout restart function with configurable interval; default setting is 30 minutes. shortconnection maintenance time. Serial port cache cleaning function for improved reliability. 3. Modbus and data management Supports multiple simultaneous open servers; each server can handle up to 5 client connections. Compatible with a variety of Modbus gateways to enable active reporting of RTU devices. Supports Modbus TCP and Modbus RTU intertransfer; can be configured as storage mode to automatically collect device data, or in a questionandanswer multihost mode. 4. Protocols, data reporting, and cloud access Supports Modbus data active reporting and TCP transparent transmission servers, as well as MQTT servers. HTTP client mode using HTTP/1.1; supports GET and POST requests. MQTT gateway function enables access to AliCloud and standard MQTT 3.1.1 servers (OneNET, Baidu Cloud, Huawei Cloud, etc). Typical applications Industrial automation and remote equipment monitoring: connect RTU devices via Modbus gateways, report data in real time to a central server or cloud, and efficiently manage multiple clients across several gateways. Distributed facilities with mixed RS485/RS232 devices: leverage the isolated version for safe operation, robust port protection, and reliable communication in noisy environments. Cloudenabled monitoring and control: use the MQTT gateway to AliCloud or other MQTT servers, and HTTP/REST endpoints for integration with enterprise systems and dashboards.