摘 要：随着我国经济和文化实业的发展，在很多公开竞争场合要求有公正的竞争裁决，诸如证券、股票交易及各种智力竞赛等，因此出现了抢答器。最初的抢答器是由优先编码器构成的逻辑电路，其运算速度慢，线路复杂，可靠性不高，功能也比较简单，特别是当抢答路数很多时，实现起来更加困难。因此，一种能够体现竞赛的公开、公平、公正性的知识竞赛抢答器成为一种需求。本课题以PLC和组态技术为核心设计了一个智能抢答系统，其电路结构简单，控制灵活方便，可扩展性强，只要改变输入PLC程序，便可改变系统的抢答方案，系统经整机调试达到了原设计要求。

关键词：PLC；抢答器；七段数码器；I/O分配

Abstract：With the development of our country economy and cultural industry, public competition requires a fairadjudgementin many occasions,such as securities and ruling stock trading and various intelligence contest etc, resulting in various responder. First vies to answer first is composed of priority encoder which is constiuted by logic circuit, the speed and reliability of it is not high and the circuit is complex, but the function is simple. Especially when there are many responders, it is more difficult to achieve. Therefore, a responder to reflect a kind of openness, fairness and impartiality of the knowledge competition is a kind of demand occupations.The task is a answering system based on intelligence, and the core of this is based on PLC and Configuration technology .The design not only retains the basic function of the the original responder but increases a series of practical function and simplifies the circuit structure, it will be easy and flexible to its control, as long as change the PLC control procedures, you are able to change the program of the competition responder.After the whole machine debugging , reached the original design requirements.

Key words：PLC; the knowledge competitionresponder;7 digital device;I/O distribution