本文首先简要地介绍在数据传输中终端设备与传输设备之间的接口关系和异步数据信号的格式;然后着重讨论在调解器中对数据终端来的异步信号进行同步转换的原理及其具体电路;并在描述电路工作原理的基础上,对电路的传输性能作简单的分析与讨论,同时对其使用的场合作一些介绍。 This article first briefly introduces the interface between the terminal equipment and the transmission equipment and the format of the asynchronous data signal in the data transmission. Then it focuses on the principle and the concrete circuit of synchronizing the asynchronous signal from the data terminal in the modem. And on the basis of describing the working principle of the circuit, the transmission performance of the circuit is briefly analyzed and discussed. At the same time, some introduction is made on the field of its use.