libmodbus

Comprehensive Analysis of Siemens PLC Communication Protocols: A Guide to Applications of PROFIBUS, PROFINET, Modbus, and Other Network Technologies

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Comprehensive Analysis of Siemens PLC Communication Protocols: A Guide to Applications of PROFIBUS, PROFINET, Modbus, and Other Network Technologies

Follow us | Discover more exciting content Alright, I will write this technical article about PLC communication protocols as “Pig Brother”. Hello everyone, today we will talk about the “nervous system” of industrial automation – PLC communication protocols. In the industrial field, data transmission between devices is as important as the human nervous system. This … Read more

Case Study: Timed Polling Program Based on S7-1200 Modbus RTU

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Case Study: Timed Polling Program Based on S7-1200 Modbus RTU

For more exciting content, click to follow “PLC Enthusiasts” The Siemens S7-1200 can communicate via Modbus RTU through communication modules, with the PLC serving as the controller, typically acting as the Modbus master. When functioning as a Modbus master, it generally polls parameters from multiple slave devices. This article introduces the timed polling program for … Read more

Detailed Explanation of Modbus Protocol and Data Types

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Detailed Explanation of Modbus Protocol and Data Types

Click 👆 above to follow Engineer Yan Ji and ★star★. Protocol Definition 1. Modbus is a request-response protocol implemented using a master-slave relationship. 2. The Modbus protocol introduces different application data units to change the packet format used in serial communication or to allow the use of TCP/IP and User Datagram Protocol (UDP) networks. Its … Read more

MODBUS Communication Function of Siemens S7-200 Series PLC (Part 1)

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MODBUS Communication Function of Siemens S7-200 Series PLC (Part 1)

Click on the top “Technical Training” to select “Pinned Public Account” Over 110,000 industrial control professionals follow this WeChat platform: Technical sharing, learning exchange, industrial control videos Recently, many students have been asking about the MODBUS communication of the S7-200 series PLC, so today I will write an article to discuss how to use the … Read more

Understanding Modbus TCP Protocol and Communication Messages

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Understanding Modbus TCP Protocol and Communication Messages

1. Design Philosophy of Modbus Protocol Modbus devices communicate using a master-slave (client-server) architecture, where only one device (the master/client) can initiate transactions (referred to as queries). Other devices (slave/server) respond by providing requested data or performing operations as requested in the query. Slaves are any peripheral devices (I/O converters, valves, network drives, or other … Read more

CANopen Distributed IO Couplers Provided by Our Company

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CANopen Distributed IO Couplers Provided by Our Company

In order to achieve information collection and command output over as large a range as possible, we need to distribute the IO through a fieldbus. How can this be achieved? The answer is to connect several IO couplers on the communication bus, which communicate data with controllers such as PLC. The PLC and other controllers … Read more

RS-232, RS-422, RS-485, and Modbus: A Detailed Explanation of Industrial Communication Standards

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RS-232, RS-422, RS-485, and Modbus: A Detailed Explanation of Industrial Communication Standards

These communication standards play different roles in industrial automation. Let me use a traffic system analogy to help you understand: Basic Positioning of the Four Standards 1. RS-232: A One-to-One Small Road Features: The earliest serial communication standard (1969) Point-to-point full-duplex communication (simultaneous two-way) Single-ended signal transmission (susceptible to interference) Typical transmission distance ≤ 15 … Read more

Application of PXB-6021: Transforming Modbus IO Modules into CANopen IO Modules

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Application of PXB-6021: Transforming Modbus IO Modules into CANopen IO Modules

In modern industrial control, we often encounter situations where Modbus IO needs to connect to CANopen IO. How can we achieve interoperability between these two different communication protocols? PXB-6021 is a newly launched Modbus to CANopen protocol converter from Zhiyuan Electronics. It features 1 CAN channel, 1 100Mbps Ethernet port, and 1 RS485 port.This product … Read more

Comprehensive Analysis of MCU-PLC Serial Communication Protocol

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Comprehensive Analysis of MCU-PLC Serial Communication Protocol

Hello everyone, I am Da Yi, and today we are going to talk about the serial communication protocol between microcontrollers (MCU) and PLCs. When it comes to serial communication, many of you might feel confused, but don’t worry, I will clarify everything shortly. What is Serial Communication?Communication is everywhere; for example, the way you and … Read more

Essential Tips for Upgrading Industrial Control Systems: Perfect PLC and Inverter Coordination

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Essential Tips for Upgrading Industrial Control Systems: Perfect PLC and Inverter Coordination

I remember when I first joined the industry, I took over a project to upgrade an injection molding machine. The communication between the inverter and the PLC was always intermittent. After several days of troubleshooting, I discovered that the grounding was not done correctly, which caused interference. Today, I will share my experiences and techniques … Read more