1. Overview

DTU (Data Transfer Unit) transparent transmission mode is the core technology of the Industrial Internet of Things. It is like a transparent data pipeline. It does not do any parsing or modification, and directly forwards the original byte stream of the terminal device (such as sensor data, PLC instructions) to the server through the wireless network. This "zero processing" mechanism ensures the integrity and real-time performance of the data, and is especially suitable for non-standard protocol scenarios.

2. Theoretical basis

Transparent transmission: DTU only acts as a data relay, does not parse the protocol header, does not modify the content (such as Modbus CRC check), and directly encapsulates it as a TCP/UDP packet for transmission.
Example: The sensor sends a hexadecimal frame 0x01 0x03… → DTU → server, without intervention throughout the process.
Two-way low latency: supports two-way communication from device → server (uplink) and server → device (downlink), without data processing, and the latency is lower than the protocol conversion mode.
Adaptive protocol: compatible with Modbus, MQTT, and custom private protocols, only serial port parameters (baud rate, check bit) need to be matched.
Key technology optimization
Heartbeat keep-alive: heartbeat packets are sent regularly to prevent NAT timeout and disconnection.
Dynamic packet subdivision: large data frames are transmitted in packets according to sequence numbers to avoid packet loss due to network fluctuations.
Dual-mode network switching: 4G/NB-IoT is automatically switched according to signal strength to improve stability in remote areas.
Supports LoRa+4G+satellite communication redundant links, suitable for extremely remote areas (such as power transmission monitoring in mountainous areas).

3. Typical application scenarios

Industrial control: PLC transmits production line temperature/pressure data to the cloud platform in real time.
Smart agriculture: Soil moisture sensor triggers irrigation system through LoRa transparent transmission.
Smart home: Mobile phone commands are directly transmitted to the thermostat, and the response delay is <100ms.

4. Chengdu Ebyte product recommendation

4.1 E90-DTU (400SL30L)-Low-power wireless data transmission radio
Features: ①New generation flagship LoRa spread spectrum anti-interference
②Support standard ModBus protocol
③Support dual power control (battery) + reverse charging + ultra-low power consumption

4.2 E90-DTU (400SL30-4G)-V2.0
Features: ①4G full network access (China Mobile, China Unicom, China Telecom)
②Storage gateway saves instructions, automatic polling, ultra-low data delay
③Support standard MQTT protocol, Mod

5. Summary

DTU transparent transmission mechanism has become the data backbone of the industrial Internet of Things with zero analysis and high real-time performance. Its core value lies in protocol compatibility and low latency. Although there are limitations such as security dependence on external processing and low bandwidth utilization, the robustness can be significantly improved through optimization methods such as heartbeat packets, dynamic packet subpackaging, and edge encryption. In the future, with the integration of 5G and AI edge computing, transparent transmission technology will evolve towards an intelligent decision-making closed loop and become the core of Industry 4.0 and smart.