NPN与PNP的PLC接线方式 PLC wiring method for NPN and PNP

PNP是输出与电源共用负极，控制正极通断，输出正电压；NPN则相反，输出与电源共用正极，控制负极通断，输出负电压。

PNP shares the negative pole with thepower supply, controls the on/off of the positive pole, and outputs a positivevoltage; On the contrary, NPN shares the positive pole with the power supply,controls the on/off of the negative pole, and outputs a negative voltage.

日系如三菱比较喜欢用NPN，欧美如西门子喜欢用PNP。不过现在大多数的产品都是支持两种接法的。

Japanese brands like Mitsubishi preferto use NPN, while European and American brands like Siemens prefer to use PNP.However, most products now support two types of connections.

但是一般同一个PLC的输入信号类型只能选用其中一种。临时应急使用的话，可以用小型继电器转换信号极性。

However, generally only one type of inputsignal can be selected for the same PLC. For temporary emergency use, a smallrelay can be used to convert signal polarity.

PLC漏型输入接线   PLC leaky input wiring

漏型输入与接近开关连接   Leakage type input and proximity switchconnection

NPN、PNP型传感器都是利用三极管的饱和和截止的两种状态；

Both NPN and PNP type sensors utilizethe saturation and cutoff states of the transistor;

I/O点为例，源型就是电流从I/O点流出；漏型，就是电流通过I/O点流入；

For example, the source type is thecurrent flowing out from the I/O point; Leakage type refers to the currentflowing into the I/O point;

NPN，当有信号触发时，信号输出线OUT和GND连接，相当于OUT输出低电平。

NPN, when a signal is triggered, thesignal output lines OUT and GND are connected, equivalent to OUT outputting alow level.

PNP，当有信号触发时，信号输出线OUT和VCC连接，相当于OUT输出高电平。
PNP, when a signal is triggered, the signal output line OUT is connected toVCC, equivalent to OUT outputting a high level.

它们输出高低电平都是和它们自己的工作特性特性有关，可以参考模拟电子线路。

Their output high and low levels arerelated to their own working characteristics, which can be referred to asanalog electronic circuits.