In the wave of smart manufacturing, connecting industrial equipment to the network marks the starting point for data flow. However, traditional industrial sites often face challenges such as incompatible device protocols, complex network environments, and high stability requirements. The 4G modem serves as the core hub connecting field devices to the cloud, with its configuration efficiency directly impacting project implementation timelines. This article takes typical application scenarios of 4G modems as a starting point, dissecting in detail the five key steps for device networking, and sharing practical pitfall avoidance guides to help engineers complete the entire process from unboxing to cloud data transmission within one hour.
The essence of a 4G modem is a dedicated device for protocol conversion and data transparent transmission, with its core functions summarized in three points:
Protocol Adaptation: Converts industrial protocols such as Modbus RTU and CAN bus into internet protocols like TCP/IP or MQTT.
Network Bridging: Supports multiple network formats including 4G/5G, Wi-Fi, and Ethernet to adapt to different field environments.
Edge Processing: Features edge computing capabilities such as data caching and offline resumption to enhance system reliability.
Take the case of an automotive parts factory: By deploying the USR-G771 4G modem, RS485 interface data from 30 old CNC machines was converted into MQTT protocol and uploaded to a private cloud platform, enabling real-time monitoring of equipment OEE (Overall Equipment Effectiveness). The transformation period was shortened from three months under traditional solutions to just two weeks.
Confirm that the modem's interface type (e.g., RS232/RS485/CAN) matches the field devices.
Check the operating temperature range (industrial-grade products typically support -40°C to 85°C).
Evaluate network coverage and equip with external antennas to enhance signal strength if necessary.
Fixed IP Address: Suitable for scenarios requiring active access to the modem (e.g., remote operation and maintenance).
Dynamic Domain Name System (DDNS): Saves public IP costs but requires consideration of domain name resolution stability.
Virtual Private Network (VPN): Essential for scenarios with high data security requirements.
Essential Tools: Serial port debugging assistant, network cable tester, insulating tape.
Recommended Software: USR-G771 configuration tool (supports Windows/Linux).
Testing Equipment: Backup power supply, simulated load (for verifying data collection).
Wiring Specifications: Use shielded twisted-pair cables for RS485 connections, ensuring strict correspondence of A/B wire sequences.
Power Supply Scheme: Preferably use a 24V DC power supply and avoid sharing power with high-power devices.
Grounding Treatment: Reliably ground the modem casing to the equipment rack to suppress electromagnetic interference.
Pitfall Avoidance Guide: In a chemical project, the modem frequently restarted during thunderstorms due to lack of grounding. The issue was resolved by adding grounding electrodes.
Connect the modem to a computer via a serial cable and open the configuration tool.
Set the working mode: Choose "Transparent Transmission" or "Modbus Gateway" mode.
Configure network parameters:APN settings (for mobile networks).
Server address (IP or domain name).
Port number (default recommendation: use non-standard ports above 8000).
Save the configuration and restart the device.
Advanced Tip: Use the USR-G771's "SMS Configuration" function to remotely modify parameters by sending specially formatted SMS messages, suitable for remote sites without on-site engineers.
Modbus Devices: Configure slave addresses, function codes, and register mapping tables.
Custom Protocols: Implement data parsing through HEX instruction templates.
Data Format Conversion: Set conversion rules for special data types such as floating-point numbers and BCD codes.
Practical Case: A photovoltaic power plant used the USR-G771's "Protocol Self-Learning" function to automatically identify the private protocol of inverters, reducing protocol development work from two weeks to just two days.
Use the ping command to verify network connectivity.
Test port openness via telnet.
Analyze data transmission quality using network packet capture tools (e.g., Wireshark).
Simulate offline scenarios to verify offline resumption functionality.
Performance Indicator References:
Mean Time Between Failures (MTBF): Recommend products with >50,000 hours.
Data Retransmission Delay: Quality modems should have <3 seconds.
Network Switching Time: Dual-SIM dual-standby products should have <10 seconds.
Choose a suitable industrial IoT platform (e.g., Alibaba Cloud IoT, AWS IoT).
Configure Device Shadow for state synchronization.
Set up data visualization dashboards and alert rules.
Develop API interfaces for integration with MES/ERP systems.
Architecture Optimization Suggestions:
Use MQTT+SSL encrypted transmission for data security.
Deploy edge gateways for local data preprocessing.
Use time-series databases (e.g., InfluxDB) for equipment data storage.
Check SIM card status (whether in arrears or poorly connected).
Verify APN settings are correct.
Adjust heartbeat interval (recommended 60-300 seconds).
Check serial port parameters such as baud rate, data bits, and stop bits.
Confirm no device address conflicts exist.
Enable data verification (e.g., CRC16).
Prefer modems supporting dual-SIM dual-standby (e.g., USR-G771).
Configure network priority strategies.
Adjust reconnection attempt counts and intervals.
With the development of Industry 4.0, modems are evolving from simple data transmission devices to intelligent edge terminals:
AI Empowerment: Built-in anomaly detection algorithms enable predictive maintenance of equipment.
Low-Power Design: Support for low-power wide-area network technologies such as LoRaWAN.
Containerized Deployment: Allow users to customize edge applications (e.g., Python scripts).
Digital Twin: Data collected by modems directly drives virtual equipment models.
Take the upgraded version of the USR-G771 as an example. Its new edge computing module can run lightweight machine learning models locally, enabling basic data analysis even during network outages and significantly enhancing system robustness.
Configuring 4G modems should not be a technical barrier but rather a "standard toolkit" for engineers. Through standardized configuration processes, visual debugging interfaces, and intelligent fault diagnosis, modern DTU products have reduced deployment times from days to hours. For enterprises advancing digital transformation, it is recommended to start with mature products like the USR-G771 to quickly validate business value before iterative upgrades. Remember: In the era of industrial IoT, connecting devices is just the starting point; the real challenge lies in creating value from data.
