程控交换机实验仿真系统的开发与研究
摘要
    随着现代通信技术的迅速发展与日益普及，程控交换原理与技术作为目前通信领域中应用最广的专业基础知识，已成为各高等院校电子通信类专业教学的核心课程之一。该课程侧重介绍程控交换的基本概念和工作原理，课堂教学内容迫切需要相应的实验辅助，以达到帮助学生正确掌握和深入理解课程内容的目的。
    本文结合程控交换原理课程及其教学实践要求，开发了一套用于教学演示及实验使用的小型程控交换机仿真系统。该系统包括了程控交换机的所有基本部件：以单片机为核心的控制系统、四个用户接口、两个中继接口、8⨯模块化设计的优点16交换网络以及信号发生源等，能够实现自动局内呼叫处理、出局呼叫处理以及入局呼叫处理。同时学生可在该硬件平台下借助单片机仿真器自由的编写程控软件。能够开设程控交换机课程中的用户接口实验、中继接口实验、控制系统的实验(包括硬件实验和软件编程实验)、交换网络实验等，满足了实验课程的要求。
本文首先介绍了各部分的硬件实现，在控制软件的设计中通过建立合理的软件模型来解决系统的实时性和并发性的问题，最后给出了此类软件的CAD系统设计的方法。
关键词 程控交换机；中继接口；双音多频；仿真系统
                                   
The research and development of the experimental system of the SPC exchange
Abstract
  With the rapid development of communication technology, the curriculum of the SPC exchange theory has become the basic core in the colleges as the most important knowledge in the field of communication. And most of this knowledge has to been transferred to the students by practice, so we need a set of simulation of the SPC exchange.
    According to the theory of SPC exchange, we devise and develop an experimental system of automatic exchange to meet the need of teaching and practice. It is a monotype of PBX with a Single Chip Microcosm as the hardcore, it has four customer and one relay interfaces, a 8×16 exchange network, along with a keyboard as input and several LEDs as
output. We can communicate within the local telephone exchange and also with the other phones in the other exchanger. It has the function of conference calling, manual exchange and PCM exchange etc.
Based on the brief analysis of working state of the PBX, we set up a frame model of the software, and the main arithmetic which make up of this model are given. And then we recommend the technique of the software CAD. At last, we validate the software on the PBX controlled by SCM.
Keywords　 SPC Exchange；Relay interface；Dual Tone Mutifrequency；Virtual system
不要删除行尾的分节符，此行不会被打印
摘要    I
Abstract    II
程控软件的二次开发平台    9
信号音控制电路    27