https://www.linkedin.com/learning/input-sensors-with-plc-sinking-and-sourcing

In industrial control systems, sensors are used to help the controller programs perform their tasks and capabilities. Sensors are part of the industrial field level to check products, they are also used to ensure safety of the equipment, products, and operators. One of the common ways to connect digital input sensors to PLC is using sinking or sourcing wiring circuits. In this course, instructor Zahraa Khalil covers the basic differences between sinking and sourcing terminologies when working with PLC. She also gives an overview of PNP and NPN sensors when used in sourcing and sinking circuits, and shows some examples of the wiring.