In the world of industrial Internet of Things, there are two "old acquaintances" that are almost inseparable: one is the "messenger" responsible for remote data transmission - industrial DTU, and the other is the "common language" for communication between devices - Modbus protocol.
You might be curious: in today's era when protocols are emerging one after another, why does DTU, this "messenger", have a special fondness for Modbus, this "old buddy"? Isn't there a younger and cooler "language"?
🤔 Today, let's dig into the secrets behind this "golden pair".
Imagine that your computer needs to be connected to various devices: keyboard, mouse, USB flash drive, printer... If each device had a unique interface, the back of your computer would have long been a tangled mess, like a "silk hole".
Fortunately, we have USB. One interface, handle everything.
In industrial equipment, Modbus plays a role similar to USB. It is like a standardized "plug". Whether it is a Siemens PLC, a Schneider frequency converter, or various domestic intelligent instruments and sensors, as long as they support Modbus, the DTU can easily "plug" them in to read the data.
This "plug-and-play" compatibility is the first and most important reason why they came together.
Modbus is a completely open protocol and is not affiliated with any company. This means it is like the "Mandarin" of the industrial sector. No matter which "dialect area" (brand) the equipment comes from, it can be used for barrier-free communication.
This is simply a huge blessing for DTU:
No need for a "translator"：DTU does not need to develop a dedicated driver program for each brand of device. As long as it masters the "language" of Modbus, it can communicate with the vast majority of devices.
Break down brand barriers：Users can freely choose the device combination with the best cost performance without worrying about being "kidnapped" by a certain brand. The freedom of system integration is extremely high.
Many modern industrial protocols are powerful in function but complex in configuration, like a thick "heavenly book". And Modbus is so simple and cute.
It adopts a master-slave question-answering mode, with logic as clear as a primary school student's dialogue:
DTU (Master Station）："Hey, Device A, please give me your temperature data!"
Device A (Slave Station）：“Ok. My temperature is 25.5℃。”
Back and forth, straightforward and efficient. This simple data model (mainly read-write registers) significantly reduces the development workload of engineers, enables faster product launch, and makes debugging more convenient. For enterprises, time is money and simplicity is efficiency.
This is the most "connected" aspect between DTU and Modbus!
We know that a large number of old devices in the factory use serial communication (such as RS485) and run the Modbus RTU protocol. To transfer the data to the cloud platform, we use network communication (such as 4G/5G/ Ethernet) and run the Modbus TCP protocol.
Between the two, there is only a "translator" missing.
And industrial DTU is precisely this innate "translator"!
One of its core tasks is to seamlessly "package" the Modbus RTU data on the serial port into Modbus TCP data packets and send them out through cellular networks or wired networks. And vice versa.
This process is transparent to the user. You can't feel any trace of conversion, as if the device itself has a "network cable". The combination of DTU and Modbus has perfectly solved the century-old problem of "dumb devices" accessing the Internet.
In business, cost is an unavoidable topic.
Low hardware cost：The chip and module technologies that support Modbus are very mature and extremely low in price. This makes the overall cost of both Dtus and terminal devices highly competitive.
Low development and maintenance costs：The protocol is simple, which means a short development cycle and relatively low requirements for engineers' skills. Meanwhile, due to its high popularity, there are plenty of debugging tools, technical documents, and community support available online, making later maintenance both worry-free and cost-effective.
It is like the "national magic car" in the field of industrial communication. It may not be the most luxurious or technologically advanced, but it is definitely the most robust, economical and capable of solving practical problems.
Of course, we are not saying that Modbus is flawless. In complex scenarios such as data security and large-scale models, more modern protocols like OPC UA and MQTT do have their advantages.
But why does DTU still "deeply love" Modbus?
Because it addresses the most core and common pain point in the industrial Internet of Things: how to connect a vast number of heterogeneous, especially the huge existing traditional devices to the Internet in a simple and reliable way at the lowest cost and with the highest efficiency.
It doesn't pursue the latest trends, but only the most practical ones. This pragmatic "craftsman spirit" might precisely be the fundamental reason why it has always maintained strong vitality in the ever-changing industrial world.
So, what do you think the future of Modbus will be like? Share your thoughts in the comment section!