Today we continue to review the history of PLCs and the evolution of industrial automation. For the first part, see: The History of PLCs and the Evolution of Industrial Automation (Part One). Part Two: Siemens entered this field in 1976 with the launch of a product called S3. Prior to this, Germany had used an … Read more
[Background] In April 2025, a move by Audi’s Böllinger Höfe factory in Germany shocked the automation industry: they removed 200 traditional PLCs from the production line and replaced them with virtual PLCs (vPLCs) running on Siemens’ cloud. The control logic shifted from “hardware next to the machine” to “software in a data center kilometers away,” … Read more
In the field of industrial automation, PLCs are core control devices, and SFC (Sequential Function Chart), as a programming language defined in the IEC 61131-3 standard, has become a standard skill for senior PLC engineers. Why is SFC so popular in complex automation projects? 1. What is SFC? Why do Senior Engineers Favor It? SFC … Read more
Similar to other programming languages, the IEC 61131-3 programming standard provides various data types, including basic types and composite types. The data type determines the memory capacity required for variable values, thereby limiting the maximum and minimum values that can be stored in the variable. In this issue, we will focus on the data types … Read more
The International Electrotechnical Commission (IEC) standard IEC 61131-3 defines five main PLC programming languages, each suitable for different types of control tasks and program complexities. Below is a detailed analysis of how PLC multilingual programming adapts to complex programs. 1. The Five Programming Languages Defined by IEC 61131-3 1. Ladder Diagram (LD) • Characteristics: A … Read more
“PLC Multilingual Programming: Seamless Collaboration in International Projects, Boosting Development Efficiency by 50%!” An incident at a European automotive factory: The German team wrote control logic using ladder diagrams, while the Italian team modified the program using instruction lists. As a result, a language compatibility issue caused a 48-hour production line shutdown, leading to a … Read more
The editor has shared an article titled “Where Does the Greatest Sense of Achievement Come from as an Electrical Engineer?” which has garnered much attention from netizens. Today, we are sharing another article by Teacher Zhang, discussing the topic of “How to Learn PLC” in hopes that everyone can find inspiration from it. PLC is … Read more
Most PLC programming consists of input contacts and output coils, which influence real-world outcomes through logical series/parallel combinations. —————————————————— Although each model of PLC seems to have its unique programming standards, there is indeed an international standard that most PLC manufacturers at least attempt to follow. This is the IEC 61131-3 standard, which will be … Read more