Explore our top-tier fieldbus and Ethernet conversion solutions engineered for seamless plant floor integration.
In the modern landscape of industrial automation, the integration of Operational Technology (OT) and Information Technology (IT) represents the cornerstone of Industry 4.0. At the heart of this integration lies the translation of protocols. The Modbus protocol—specifically Modbus RTU/ASCII running over RS485/RS232 serial networks—remains one of the most widely deployed industrial communication protocols globally. However, modern plant architectures, SCADA systems, Enterprise Resource Planning (ERP) databases, and Cloud IoT frameworks rely on Ethernet-based TCP/IP communication. The Modbus IP Gateway acts as the vital bridge, converting serial registers into network packets and enabling deterministic, bi-directional transmission between microcontrollers, PLCs, DCS nodes, and higher-level networks.
As a leading China Modbus IP gateway manufacturer and factory, Jiaxing Songmao Electronics Co., Ltd. has spent over 18 years engineering communication converters that resolve the complex issues of network latency, galvanic isolation, and electromagnetic interference (EMI). Whether you are querying field transmitters, collecting multi-channel HART signals, or linking old-world infrastructure to a gigabit Ethernet backbone, our products ensure zero data frame loss and 24/7 reliability in hazardous and demanding industrial environments.
Traditional HART transmitters and RS485 loop-powered sensors contain vast amounts of diagnostic data (secondary, tertiary, and quaternary variables) that never reach the control room because legacy PLC input cards only read the basic 4-20mA analog signal. Our Modbus IP gateways and HART data collectors extract this rich diagnostic information, converting it into standard Modbus TCP/IP registers accessible by any SCADA or IIoT platform.
Understanding the architectural differences between protocol converters and data collectors is key to optimized procurement.
| Parameters / Features | Serial to Ethernet Servers (SM700 Series) | HART to Modbus RTU/TCP Converters | Multi-Channel Data Collectors |
|---|---|---|---|
| Primary Interface | RS485 / RS232 / TCP/IP Ethernet | HART FSK Loop / RS485 (Modbus RTU) | 8 / 16 / 32 Channels HART Inputs |
| Baud Rate Range | 300 bps to 115.2 Kbps | 1200 bps (HART Fixed) / Up to 115.2 Kbps | 1200 bps per channel / 115.2 Kbps RTU |
| Isolation protection | 1.5kV Electromagnetic Isolation | Optocoupler / 1.5kV Galvanic Isolation | Multi-channel independent isolation |
| Supported Protocols | Modbus TCP, Modbus RTU, TCP Client/Server, UDP | HART, Modbus RTU, Modbus TCP | HART (Master), Modbus RTU/TCP (Slave) |
| Best Applications | PLC communication, serial instrument networking | HART flowmeters, pressure transmitters, valves | Large-scale petrochemical process diagnostics |
Browse our dual-line portfolio of specialized industrial protocol gateways designed for targeted OT topologies.
4-20mA, modbus protocol, GPRS remote collector. A high-tech product for remote telemetry.
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hart to modbus, hart to 485, HART Intelligent Transmitter for customized automation setups.
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Combining RS232/RS485 communication with HART network nodes for standard industrial applications.
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Hart to Modbus, Hart to 485, and Hart to 232 conversion built on proprietary MCU architecture.
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485 to 4-20mA, modbus protocol, Multi-channel current output. Highly reliable analog transmitter.
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485 to tcp, 232 to tcp, modbus protocol conversion over robust RJ45 ethernet connections.
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485 smart converter, modbus protocol converter with auto-direction control and adaptive baud rates.
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485 smart converter, modbus protocol multiplexing, facilitating reliable multi-instrument pooling.
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High density HART data polling to Modbus TCP and RTU structures for SCADA interface.
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High isolation multivariable conversion matching legacy analog transmitters with PLCs.
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Providing robust 4G network backhaul for isolated sensor loops and field transmitters.
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Designed for high-density applications in large chemical plants and petrochemical refineries.
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Simultaneous polling of 16 process transmitters, with robust power and signal isolation.
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Optically isolated 8-channel collector mapping HART registers directly to RS485 loops.
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Robust Modbus TCP/IP translation featuring dedicated web page utility for calibration.
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HART to Modbus TCP and RTU, designed for standard DIN-rail mounting in distribution cabinets.
Product DetailsSystem integrators and procurement departments in Western Europe, North America, Southeast Asia, and Latin America face significant hurdles when sourcing industrial protocol converters. The primary requirements of global enterprises focus on three pillars: hardware stability, strict standard compliance, and cost-to-performance efficiency.
In petrochemical refineries, municipal water facilities, and steel plants, field instruments are often scattered over large distances. Standard RS485 communication is prone to ground loop potential differences and lightning surges, which can burn out expensive PLC/DCS I/O modules. Global buyers prioritize converters with 1.5kV to 3.0kV galvanic and electromagnetic isolation. In addition, device power schemes must adapt to typical industrial standards (e.g., 24VDC) with polarity reversal protection, and wide operating temperature specs (-40°C to +85°C) to withstand sub-zero winters or Saharan desert heat in mining fields.
Songmao Electronics addresses these concerns by implementing rigid industrial-grade components, omitting commercial-grade alternatives. All circuits are optimized with high ESD protection, and we run our products through multi-point thermal chamber testing prior to delivery. By choosing a manufacturer with complete, in-house circuit design control, global clients bypass third-party margins, ensuring highly competitive wholesale pricing without sacrificing quality.
At the center of the Songmao Modbus IP Gateway and HART Protocol Converter range is a high-speed ARM Cortex processor paired with an advanced real-time operating system (RTOS). The firmware executes rapid, non-blocking polling cycles, executing queries on the HART loop or serial network and writing the results directly into pre-mapped internal Modbus memory space. Here is an insight into our technical design:
Jiaxing Songmao Electronics Co., Ltd. was established in 2007. It has always been driven by technological innovation, deeply engaged in the field of industrial automation, and gradually developed into a high-tech enterprise integrating R&D, production and sales. The company focuses on the independent research and development of core technologies such as HART protocol communication products and data collectors. Through continuous technological breakthroughs and market expansion, it has established a leading position in the industry.
Our engineering division works closely with research universities to push the boundaries of industrial protocol conversion. From standard DIN rail mounting enclosures to customized OEM embedded PCB boards, Songmao provides reliable solutions for system integrators globally.
Delivering reliable data acquisition and protocol conversion across highly critical industrial infrastructures.
Our quality management matches top-tier international testing standards, giving global clients peace of mind.
Stay up to date with our detailed walkthroughs, product development logs, and protocol integration tutorials.
Jul 2026
MODBUS TCP (Transmission Control Protocol) is a widely used serial communication protocol in industrial environments. Learn the routing, wiring, and network configuration principles.
Jul 2026
In industrial automation, intelligent instruments, PLC control systems, and IoT data collection modules, mapping RTU registers correctly forms the foundation of reliable analytics.
Jul 2026
An in-depth explanation of the master-slave dynamic query mechanism, detailing timing control and scan schedules for optimizing field bus throughput.
Jun 2026
Configuring and calibrating field transmitters via standard HART Modems (SM100 series) with tools like Emerson Field Communicators or Pactware FDT/DTM systems.
Jun 2026
A step-by-step troubleshooting guide utilizing software logic analyzers to verify hexadecimal frames and detect timing delays over copper wires.
Jun 2026
The definitive resource on functional code differences (03 Read Holding Registers vs. 04 Read Input Registers) and packet formats for new engineers.
The technological direction of industrial automation is steering towards Edge Computing and IIoT protocols such as MQTT and OPC UA. While traditional Modbus TCP/IP works exceptionally well within local area networks (LANs), it lacks native support for report-by-exception and cloud data broker integration across WAN topologies. The future generations of Modbus IP gateways act as edge nodes, actively caching Modbus register values and publishing them as lightweight JSON payloads over MQTT to cloud environments like AWS IoT Core, Microsoft Azure, or private EMQX brokers.
Songmao Electronics is committed to this technical roadmap, continuously updating our hardware and firmware platforms. By integrating MQTT clients directly into our serial servers and multi-channel collectors, we enable smart factories to connect legacy Modbus hardware to cloud analytics engines with zero additional PC gateways. This drastically simplifies the OT architecture, reducing deployment costs and minimizing potential failure nodes on the plant floor.
In heavy industrial environments, massive electric motors, variable frequency drives (VFDs), and switching relays generate intense magnetic fields and common-mode electrical noise. Without proper isolation, these voltage surges run directly down copper RS485 differential signal lines or the 4-20mA HART loop, instantly destroying the logic gates inside central PLCs and computer motherboards.
Our converters utilize optical, magnetic, and capacitive isolators that physically decouple the field-facing hardware from the internal microcontrollers. When a surge hits the field loop, the electrical energy is blocked by the isolation barrier, keeping your central network safe. Songmao manufactures all gateways with dedicated ground terminals and high-specification TVS diodes to shunt transient voltages straight to safety, protecting your industrial assets in all operating conditions.
Find technical answers to the most common questions regarding Modbus TCP, RTU, and HART network integration.
Review the rest of our standard model lineup. Contact our sales engineers for direct factory pricing or OEM customizations.
