A PNP and NPN sensor refers to the type of electrical output used by proximity sensors to send detection signals to control systems like PLCs. Both work on the same principle of sensing an object without physical contact, but they differ in how the output current flows once detection occurs. In simple terms, an NPN sensor switches to the negative side (0V) of the circuit when activated, while a PNP sensor switches to the positive side (+V). This difference determines how each sensor is wired and what type of PLC input it is compatible with. Choosing between PNP and NPN depends on the wiring standard used in your automation system and the input configuration of the controller.
An NPN sensor, also known as a sinking output sensor, connects the load to the positive voltage and switches the signal to ground when it detects an object. These are common in systems that use sinking inputs, often found in older or Asian-made control systems. A PNP sensor, or sourcing sensor, sends a positive voltage signal to the load when activated. It is the preferred type in modern automation systems due to its simple wiring and safer output behavior—since the signal remains at a positive voltage when active. PNP sensors are easier to troubleshoot and are now widely adopted in industrial machinery and process control systems.
Autonics PNP Proximity Sensors offer reliable and precise detection for a variety of automation applications. They are built with high-quality components, ensuring accurate sensing, quick response times, and long service life. These sensors integrate easily with PLCs and controllers, providing stable performance in demanding environments such as packaging, robotics, and assembly automation. Designed for durability and consistent output, Autonics sensors help maintain smooth and efficient industrial operations.