简要介绍了集中管理式公用电话计费系统的组成及功能。系统由公用电话集中管理中心与集中管理式电话计费器组成。集中管理中心与集中管理式电话计费器之间可通过公众电话网以拨号方式建立双向通信链路 ,从而实现对集中管理式电话计费器的远程管理。文中对集中管理式公用电话计费器的硬件设计作了系统的描述。自己设计了电话计费器与电话线的独特接口电路。对计费器软件的重点 ,即摘、挂机及拨号脉冲识别程序的设计 ,提出了一套完整的理论依据 Brief introduction to the composition and function of centralized management of public telephone billing system. The system consists of a public telephone centralized management center and a centrally managed telephone meter. Centralized management center and centralized management of telephone meter between the public telephone network through the dial-up way to establish two-way communication links, in order to achieve centralized management of telephone meter remote management. The paper gives a systematic description of the hardware design of centrally managed payphone. Own design of the telephone meter and telephone line unique interface circuit. A set of complete theoretical basis is put forward on the key points of the meter software, that is, the design of pick-up, on-hook and dial-pulse recognition programs