The TIA V13 SP1 software provides two versions of Modbus RTU commands: Figure 1. Two Versions of Modbus RTU Commands The earlier version of the Modbus RTU command (MODBUS (V2.2) in Figure 1) can only communicate via the CM1241 communication module or the CB1241 communication board. The new version of the Modbus RTU command (MODBUS(RTU) … Read more
PLC Communication Protocol In modern industrial control systems, PLC is widely used. Programs can be easily modified and managed, thereby improving production efficiency, saving time and costs. The communication protocol of PLC is the communication support protocol for connecting different operating systems and hardware architectures. In simple terms, PLC usually controls the underlying layer, collects … Read more
1. Introduction The HMI (Human-Machine Interface) is increasingly used in industrial automation systems and devices due to its small size, high performance, and strong real-time capabilities. It features various displays such as letters, Chinese characters, graphics, and images, with a simple and user-friendly interface. Equipped with long-lasting membrane button keyboards, it is easy to operate. … Read more
Before we start this topic, we should understand a commonly confused issue. The difference between RS485 and MODBUS: RS485 is a physical interface, simply put, it is hardware. MODBUS is an internationally standardized communication protocol used for data exchange between devices from different manufacturers (generally for industrial purposes); the so-called protocol can also be understood … Read more
Search on WeChat Technical Training This article will introduce the detailed steps for Modbus communication between the S7-1200 PLC and the V20 frequency converter. 1. Find an S7-1200 PLC with an RS485 communication module and a V20 frequency converter. 2. Connect the RS485 module to the V20 frequency converter. The wiring method is to connect … Read more
1. Overview of MODBUS Communication The MODBUS protocol consists of MODBUS protocol over serial links and MODBUS protocol based on TCP/IP. The serial link MODBUS protocol includes MODBUS ASCII (string) and MODBUS RTU. The MODBUS protocol library provided by 200SMART supports MODBUS RTU communication. MODBUS RTU sends data in hexadecimal values. MODBUS ASCII sends data … Read more
Search on WeChat Technical Training In actual industrial automation applications, various communications are essential, such as PN communication, S7 communication, MODBUS TCP communication, and MODBUS communication, among others; however, the most widely used is MODBUS communication, as it is an open, free, and universal communication protocol. Often, during equipment debugging on the industrial site, communication … Read more
Now, let’s explain the application of MODBUS. Currently, most industrial control communication between the upper computer and the lower computer uses the communication protocol MODBUS. It is easy to imagine the importance of communication between machines. 1. MODBUS System Framework Diagram 2. Application of MODBUS The underlying communication of MODBUS uses RS485 signals connected via … Read more
When it comes to communication, many people find it difficult and feel lost. I had the same feeling when I first encountered communication concepts. I gathered a lot of materials, mostly theoretical, and it always felt like I had no starting point. After finally understanding it, I realized that the main reason for not grasping … Read more
Search on WeChat Technical Training Preparation: Hardware: Huichuan AM401 PLC, one USB to RS485 converter. Software: InoProShop (V1.6.2), Serial Assistant, Modbus-RUT slave simulator. Serial Debugging Process: 1. Program the PLC. 2. Use the Serial Assistant to check if the characters sent by the PLC are correct. 3. Connect the actual device for PLC-device debugging. (You … Read more