Today, I will present an example of interference from a variable frequency drive (VFD) on a PLC’s analog signal and a solution using a signal isolation module to overcome such interference. 1. Example 1: Phenomenon Description In a Siemens PLC, the AO point outputs a 4-20mA current control signal to a Siemens VFD, but it … Read more
PLC Application Example: Biscuit Oven Temperature Control System Increases Product Consistency by 30%! Introduction “Why do biscuits from the same batch always have different colors?” This is a quality issue that troubles many biscuit manufacturers. Today, I want to share a real PLC application case — biscuit oven temperature control system upgrade, which has improved … Read more
Click the blue text to follow! PLC Safety Control Matters: Insights from an Experienced Electrician Last month, the automated production line in Xiao Wang’s workshop suddenly crashed, and even the safety light curtain was unresponsive, almost leading to a personal injury incident. Later, the factory manager called me to check, and I found that the … Read more
Click the blue text for more exciting information Event-Driven Programming for Fault Diagnosis in Smart Home PLC Systems Over the years, I have worked on numerous smart home projects and discovered a common issue: when a fault occurs, everyone is completely at a loss! Homeowners call every day, and for a minor issue, I have … Read more
Click the blue text for more exciting information Enhancing Flexibility in IoT Applications through Object-Oriented Programming in PLCs To be honest, I have never understood why so many people think that PLC programming must use ladder diagrams. What era are we in, still drawing relay logic? After nearly 20 years in this field, those who … Read more
Click the blue text for more exciting information Remote Monitoring Solutions for Industrial Automation Driven by PLC Function Block Diagrams Just two days ago, I received a call; Old Li’s paper mill had another problem. He insisted on using that cheap domestic RTU for protocol conversion last time, and now, well, it keeps dropping connections … Read more
Today, I will introduce some control programs for single button start-stop (also known as one-click start-stop programs). This involves using a momentary button: press once to turn on a light bulb, press again to turn it off, and repeat… Although this seems like a simple program, many people may struggle to implement it. This topic … Read more
Click the blue text to follow! Old Li Talks Technology: PLC Function Blocks Make Automation Debugging Painless 1 The Emergency Repair in the Workshop Last Thursday, the automated production line in the injection molding workshop had another issue. Xiao Wang rushed to find me: “Old Li, the No. 3 injection molding machine has stopped, the … Read more
Click on the above Electrical Engineering Learning to follow and star it. A professional self-media in the field of electrical engineering, don’t miss it. 1. Bit Logic Instructions (1) Contact and Coil Instructions Programming principles of PLC ladder diagram language: 1. The ladder diagram consists of multiple rungs, each coil can form a rung, and … Read more
There are many types of PLCs, with brands generally categorized into European, Japanese, and American. The German PLCs are primarily represented by Siemens, while the Japanese brands include Mitsubishi, Omron, and Panasonic, among others. American brands include Rockwell (A-B), General Electric (GE), and Modicon. The PLC technologies in the US and Europe have been developed … Read more