A PNP and NPN sensor refers to the type of electrical output used by proximity sensors to communicate with control systems like PLCs. The difference lies in how current flows through the output circuit when the sensor detects an object. Both types perform the same function — detecting an object without contact — but the wiring and signal direction are opposite.
An NPN sensor is known as a sinking sensor. When it detects an object, it connects the output to the negative (0V) side of the circuit. The current flows from the load into the sensor and then to ground. This means the load must be connected to the positive supply. NPN sensors are widely used in older or Asian-manufactured control systems where sinking inputs are common.
A PNP sensor, on the other hand, is called a sourcing sensor. When it detects an object, it sends a positive voltage to the output. Here, the current flows from the sensor to the load and then to ground. PNP sensors are more common in modern automation systems and are compatible with PLCs that require sourcing inputs. They are generally preferred for their safety and simpler troubleshooting, as the output remains at a positive voltage when active.
Omron PNP proximity sensors are designed for reliable and precise detection in various industrial environments. They offer stable performance, fast response time, and easy integration with control systems. Built with high-quality materials and advanced circuitry, Omron’s sensors ensure long-term durability and are ideal for applications like assembly lines, packaging machines, and robotic systems where accurate detection and consistent performance are essential.