The PLC is a controller used in industry. When selecting this device, we primarily consider whether its performance meets our needs and whether the price is appropriate. Which is more important, price or performance? Clearly, performance is paramount; if the machine cannot meet the requirements, what does the price matter? Alternatively, if the performance is … Read more
1, NMT Messages CANopen devices have three states: pre-operational, operational, and stopped. By default, after startup, they automatically enter the pre-operational state, during which PDO messages cannot be sent. If PDO messages need to be sent, the device must be manually switched to operational (run) state after startup. The following message can be sent to … Read more
Table of Contents 1 Overview of CAN 1.1 What is CAN 1.2 History of CAN 1.3 CiA Organization 1.4 OSI Model of CAN 1.5 Characteristics of CAN 1.6 Topology of CAN 1.7 Data Frame of CAN 1.8 Common CAN Application Layer Protocols 2 Overview of CANopen 2.1 What is CANopen 2.2 CANopen Network Model 2.3 … Read more
Abstract CANopen is a high-level communication protocol built on the Controller Area Network (CAN), where the object dictionary is the core concept of the protocol. Mastering its related content thoroughly will allow you to use CANopen with ease and confidence. The CANopen object dictionary (OD: Object Dictionary) is the core concept of the CANopen protocol. … Read more
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