Galil DMC-1040 运动控制器

Description

Galil Motion Control DMC-1040

Galil Motion Control DMC-1040

This may seem confusing, and you may wonder why we even have different types of sensors and transistors. There are several reasons, one of which is location. Based on my experience, PNP sensors are commonly used in North America, but this is not a mandatory requirement.

There are no electrical safety standards in North America that require the use of PNP sensors; However, please consider the entire I/O system. The PNP source sensor is matched with the sinking controller input module. Each input terminal is grounded internally through the module. If the wire contacts the metal machine chassis, the result will be an inactive terminal. On the contrary, NPN sensors require a live 24V power module at each input. If any wires are loose now, a grounding fault will occur.

On the other hand, NPN transistors can transmit signals faster than equivalent PNP devices because the electron mobility of N (negative) changing particles is much faster than P (positive) charged holes in silicon devices. Therefore, for high-speed switch applications such as high-speed encoder signals or PWM (pulse width modulation) control, you may need to consider NPN type I/O modules.