S7-1200 Modbus RTU Communication Overview (Data information source: Siemens official website) Modbus has two serial transmission modes: ASCII and RTU. Modbus is a master-slave communication mode with a single master station. There can only be one master station on the Modbus network, which does not have an address. Each slave station must have a unique … Read more
01 Introduction MODBUS communication is widely used in actual industrial sites, commonly for data exchange and monitoring between PLCs and third-party devices such as inverters and instruments. 02 Example Application Below is a case study to fully understand the application of MODBUS. The specific control requirements are for Siemens 200SMART and Siemens V20 inverter to … Read more
This chapter mainly introduces the MODBUS TCP communication protocol and the content of free format communication protocols. 1. Overview of MODBUS TCP Communication MODBUS TCP combines the Ethernet physical network and the network standard TCP/IP with MODBUS as the application protocol standard for data representation. MODBUS TCP communication messages are encapsulated in Ethernet TCP/IP packets, … Read more
Search on WeChat PLC Technology In the actual application of industrial automation equipment, various communications are essential, such as PN communication, S7 communication, MODBUS TCP communication, and MODBUS communication, etc.; among them, MODBUS communication is the most widely used since it is an open, free, and universal communication protocol. However, often during equipment debugging on … Read more
We often use Bluetooth in our phones, right? For example, connecting to Bluetooth headphones to listen to music or transferring files between different devices, Bluetooth is a very convenient data transmission method. But have you ever wondered, since it is a transmission technology, why is the “Bluetooth” used in phones given such a strange name? … Read more
When learning about fire alarm systems, many people encounter the professional terms “Two-Wire Bus”, “Two-Wire System”, and “Four-Wire System”. So, what do they mean? What are the differences and application scenarios? Today, we will quickly clarify these common concepts! 1. Starting from the basics: Where do the Two-Wire Bus, Two-Wire System, and Four-Wire System come … Read more
1. Case Control Requirements 1. Equipment Used: FX3U-PLC (with 485-BD board), Mitsubishi Inverter. Control Requirements:The PLC communicates with the Mitsubishi E800 inverter to control the inverter’s forward rotation, reverse rotation, and frequency modification. 2. Hardware Wiring Instructions Open the inverter cover, and you will see a port on the circuit board that looks like a … Read more
Over 70,000 friends have followed the industrial control WeChat platform:Technical sharing,Learning exchange,Industrial control videos Solutions to RS485 Communication Port Damage in Siemens S7-200 PLC: 1. Internal RS485 Interface Circuit Diagram of S7-200 PLC: In the diagram, R1 and R2 are ordinary resistors with a resistance of 10 ohms, which serve to prevent excessive current from … Read more
The relationship between PLC and inverter is one of inclusion, where both can execute specific commands to control electric motors. The PLC is a programmable hardware for executing programs, while the inverter is one of the devices it can control. However, the PLC’s scope is broader than that of the inverter, enabling it to control … Read more
1. What Is Communication To understand RS485 communication, we first need to clarify what communication is. In fact, communication is the transmission of 0 and 1 codes between two devices, where 0 represents low level and 1 represents high level. If device A transmits data to device B, then device A and device B must … Read more