How to Establish MQTT Communication in ROS

How to Establish MQTT Communication in ROS

1. Review: Overview of ROS Communication Mechanism & Similarities and Differences with MQTT Communication Overview of ROS Communication Mechanism The main communication mechanisms in ROS are as follows: 1. Topics ○ Publish/Subscribe Model: In this communication method, nodes can publish messages to a topic or subscribe to a topic to receive messages. This method is … Read more

Why HTTP Is Not Suitable as an IoT Protocol?

Why HTTP Is Not Suitable as an IoT Protocol?

Data packets sent by IoT smart devices must be encapsulated by the corresponding protocol at each layer. With the rapid development of Internet of Things (IoT) technology, most smart devices’ communication modules support various network communication protocols such as TCP, UDP, MQTT, CoAP, HTTP, and LwM2M, which include both transport layer and application layer protocols, … Read more

Learning MQTT Protocol: Structure of Communication Packets

Learning MQTT Protocol: Structure of Communication Packets

MQTT Packet Structure In the MQTT protocol, an MQTT packet consists of three parts: Fixed Header, Variable Header, and Payload. (1) Fixed Header. Present in all MQTT packets, indicating the packet type and group class identifier. (2) Variable Header. Present in some MQTT packets, the packet type determines whether the variable header exists and its … Read more

Fundamentals of Network Communication Technology

Fundamentals of Network Communication Technology

What is a Communication Network There is a network surrounding us at all times, such as telephone networks, telegraph networks, television networks, computer networks, etc.; even within our bodies, there are many network systems, such as the nervous system and the digestive system. The most typical example is the computer network, which is a combination … Read more

Understanding Internet Protocol (IP)

Understanding Internet Protocol (IP)

I remember the first time I learned about the global Internet, I wondered what it was really like. When people told me there was a computer network covering almost all of the United States and many places around the world, the first image that came to my mind was a thick cable running along telephone … Read more

Understanding TCP with 28 Illustrations

Understanding TCP with 28 Illustrations

Source: https://juejin.cn/user/3931509313252552/postse In communication and IT work, networking is essential, and the most important protocol in the network is TCP. Whether in actual work or in written exams and interviews, you can’t escape TCP. I have read documents related to TCP in the RFC, examined the source code related to TCP in Linux, and looked … Read more

How to Achieve TCP/IP Communication Between Different PLC Networks in 7 Steps

How to Achieve TCP/IP Communication Between Different PLC Networks in 7 Steps

Introduction: In actual work environments, PLCs may communicate and exchange data. Typically, communication requires devices to be on the same network segment. However, what if our devices are not on the same segment? This article introduces how two PLCs can perform TCP/IP communication to exchange data when they are not on the same network segment. … Read more

Fundamentals of Communication Networks

Fundamentals of Communication Networks

What Is a Communication Network There is always a network around us, such as telephone networks, telegraph networks, television networks, computer networks, etc.; even within our bodies, there are many network systems, such as the nervous system and the digestive system. The most typical representative is the computer network, which is a combination of computer … Read more

Controlling V90 via MODBUS-RTU Communication

Controlling V90 via MODBUS-RTU Communication

Communication Requirements and Functions: The firmware version of V90 is V1.05 and above; V90 communicates through the RS485 interface at the top of the drive’s front panel (no additional hardware required); Pin assignment of RS485; (Pin 3 and Pin 8) Parameters can be modified, such as speed/position/torque set values via ModBus; Parameters can be monitored, … Read more

Modbus Communication Register Allocation Table for 35 Inverters

Modbus Communication Register Allocation Table for 35 Inverters

NEWS TODAY I have previously worked with microcontrollers and various inverter models including Mitsubishi D700, Siemens G120, Omron 3G3JZ, Panasonic VF200, Delta VFD-M, Xinjie VB3, Yonghong FID-B10, Shindengen IS7, Inovance MD500, Yaskawa Goodrive10, Schneider ATV12, Haiwei E, Holip HGD303, Taian F510, HEC F2A, Rockwell PowerFlex-4, Fuji FRENIC-VP, Boke CV20, Yaskawa A1000, Weichuang Artrich-AR60T, etc., using … Read more