In the wave of the Industrial Internet of Things (IIoT), automated production lines have emerged as the "secret weapon" for enterprises to reduce costs and enhance efficiency. Within this sophisticated system, the combination of 4g lte modem, PLC (Programmable Logic Controller), and HMI (Human-Machine Interface) acts like the nervous system, musculoskeletal structure, and visual system, jointly driving the intelligent operation of production lines. This article will analyze the core value and application scenarios of this combination from a practical perspective, providing actionable technical solutions for enterprise decision-makers.
PLC is the core controller for industrial automation, responsible for tasks such as logical control, sequential control, timing, and counting. For example, in automotive manufacturing, PLC achieves millimeter-level precision in body welding by controlling the grasping actions of robotic arms and the start-stop rhythm of conveyor belts. Its advantages include:
High Reliability:
Industrial-grade design supports wide-temperature operation from -20°C to 70°C, with electromagnetic interference resistance far exceeding that of consumer devices.
Flexible Programming:
Rapid adaptation to different process requirements through programming with Ladder Diagrams (LD) or Structured Text (ST).
Multi-Interface Expansion:
Supports interfaces such as RS232/RS485, Ethernet, and CAN bus, enabling easy connection to sensors, frequency converters, and other devices.
HMI serves as the window for interaction between operators and machines, displaying real-time equipment status, production data, and alarm information through touchscreens or industrial tablets. For instance, on food packaging lines, HMI can visually display parameters such as filling speed and sealing temperature, allowing operators to switch production modes with a single click. Its core value lies in:
Lowering Operational Barriers:
Graphical interfaces reduce reliance on specialized technical knowledge, enabling ordinary workers to be operational after short-term training.
Data Visualization:
Supports functions such as historical trend charts and report exports, assisting managers in analyzing production bottlenecks.
Remote Diagnostics:
Some HMIs support VPN access, enabling engineers to remotely troubleshoot issues and reduce downtime.
4g lte modem is responsible for uploading data collected by PLC to the cloud or monitoring center and receiving remote instructions. For example, in PV power plant inspections, 4g lte modem transmits 4K images captured by industrial cameras to an AI platform via a 5G network, enabling millisecond-level defect recognition. Its technical highlights include:
Protocol Conversion Capability:
Supports mainstream protocols such as Modbus and MQTT, ensuring seamless connectivity with PLCs and sensors from different manufacturers.
High-Reliability Transmission:
Ensures data integrity during network fluctuations through mechanisms like TCP Keepalive and heartbeat packets.
Edge Computing Empowerment:
Built-in AI chips enable preprocessing of images, reducing the computational load on the cloud.
An automotive components manufacturer faced the following pain points:
Low Efficiency of Manual Inspection:
Traditional visual inspections had a high missed detection rate of 5% and relied on skilled workers.
Severe Data Silos:
Production line data was stored independently, preventing global analysis.
Solution:
Hardware Combination:
Siemens S7-1200 PLC + Weinview MT8102iE HMI + Pusr's USR-G786 4g lte modem.
System Architecture:
PLC connects to laser sensors and vision cameras via IO ports to collect real-time dimensional and appearance data.
HMI displays inspection results and equipment status, supporting one-click export of production reports.
4g lte modem encrypts and uploads data to the Alibaba Cloud IoT platform, triggering work orders in the MES system.
Implementation Results:
Improved Inspection Efficiency:
AI vision inspection speed reached 0.2 seconds per piece, with the missed detection rate dropping below 0.1%.
Reduced Operation and Maintenance Costs:
Remote PLC program modification via HMI saved over 200,000 yuan annually in engineer travel expenses.
A water utility group needed to monitor pump stations in remote mountainous areas, facing the following challenges:
Poor Network Coverage: Unstable 4G signals and high costs for traditional wired solutions.
Slow Operation and Maintenance Response: The mean time to repair (MTTR) for pump station failures exceeded 8 hours.
Solution:
Hardware Combination: Mitsubishi FX5U PLC + Kunlun Tongtai TPC7062Ti HMI + Pusr's USR-DR504 4g lte modem.
System Architecture:
PLC collects data on pump current, pressure, and liquid level, transmitting it to the HMI via the Modbus RTU protocol.
HMI displays real-time curves and alarm information, supporting remote start-stop of pumps.
4g lte modem
employs multi-link redundancy technology (4G+LoRa) to ensure uninterrupted data transmission.
Implementation Results:
Improved Network Availability: Data transmission success rate increased from 85% to 99.9% through dual-link backup.
Reduced Energy Consumption: Optimized pump scheduling strategies based on HMI historical data analysis saved over 150,000 kWh of electricity annually.
I/O Points:
Reserve 20% expansion space above actual requirements. For example, a production line controlling 10 motors should opt for a PLC with ≥120 I/O points.
Scan Cycle:
Choose models with a scan cycle ≤10ms for high-speed motion control scenarios.
Communication Interfaces:
Prioritize products supporting industrial Ethernet protocols such as EtherNet/IP and Profinet.
Screen Size:
≥10 inches is recommended for operation-intensive stations, while 7 inches may suffice for monitoring stations.
Resolution:
No less than 800×480 to ensure clear graphic display.
Operating System:
Embedded Linux systems offer better stability than Windows CE but have a higher development threshold.
Network Standard:
Prioritize products supporting 5G SA/NSA dual-mode to adapt to future network upgrades.
Protection Level:
Must reach IP67 for outdoor applications, with dustproof and waterproof capabilities.
Security Features:
Support AES-256 encryption and VPN tunnels to prevent data leakage.
With the integration of AI and 5G technologies, the combination of 4g lte modem, PLC, and HMI is advancing to a new stage:
Predictive Maintenance:
Predict equipment failures by combining vibration and temperature data uploaded by 4g lte modem with machine learning algorithms.
Digital Twin:
Real-time linkage between HMI interfaces and virtual production lines, supporting simulation and optimization of process parameters.
Flexible Production:
PLC dynamically adjusts production rhythms and process routes by receiving cloud-based order information via 4g lte modem
The combination of 4g lte modem, PLC, and HMI is not a simple stack of devices but releases a "1+1+1>3" efficacy through protocol interoperability and data collaboration. For manufacturing enterprises, choosing a mature and reliable technical combination not only enhances production efficiency but also lays the foundation for digital transformation. In the race of Industry 4.0, those who can master this core technology faster will gain a competitive edge.
