【摘要】 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更多还原

【Abstract】 This paper introduces simply the composition and function of the centralized manageable message accounting system of public telephone. The system consists of the centralized management center and the centralized manageable message accounting devices. Between the center and the devices, the duplex communication links are created through the public switched telephone network, thus the remote management for the devices is realized. It describes the structure of the message accounting device. We design the special interface circuit between the message accounting device and the telephone wire. A piece of completely theoretical basis is presented in order to resolve the software design emphasis of the accounting device, such as the procedure design of off hook and on hook and dialing pulse recognition.更多还原