The Most Common S7-300 PLC Wiring Mistake (PNP vs NPN Sensors) #plc #project #automation

Have you ever connected a sensor to a PLC, only to find that the sensor works perfectly but the PLC input never turns ON? In this video, you'll learn the difference between PNP and NPN sensors, how they work, and why choosing the wrong sensor type can prevent a Siemens S7-300 PLC input from activating. ✅ PNP sensor wiring with S7-300 PLC ✅ NPN sensor wiring with relay interface ✅ Real industrial wiring examples ✅ Common PLC input wiring mistakes ✅ Practical troubleshooting tips You'll also see how to connect an NPN sensor to a Siemens S7-300 PLC using a 24V DC relay and learn why this method is not suitable for high-speed counting applications. Whether you're a PLC programmer, electrical technician, maintenance engineer, or industrial automation student, this video will help you understand one of the most important sensor wiring concepts used in industry. If you enjoy practical PLC and industrial a utomation tutorials, don't forget to subscribe and turn on notifications for future projects #plc #plc_programming #sensor #automation