换句话说，电路可以是物理双线(甚至是物理单线)、逻辑四线，它使用较少的线实现四线电路。

In other words, the circuit may be physical two - wire (or even physical one - wire) and logical four - wire, performing as a four - wire circuit but employing fewer than four wires.

youdao

换句话说，电路可以是物理双线(甚至是物理单线)、逻辑四线，它使用较少的线实现四线电路。

In other words, the circuit may be physical two - wire (or even physical one - wire) and logical four - wire, performing as a four - wire circuit but employing fewer than four wires.

youdao