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一、概述调度电话是多点通信系统,需多种通路兼容,条件复杂。现代计算机技术和微电子技术为电信科学的发展开辟了新途径,程控调度电话的开发使调度电话进入了一个新的阶段。程控调度电话由选叫和通话两个系统组成,方框原理图如图1所示。选叫信号采用频移键控调制(FSK),用八中取四(C_8~4)的组合码,传信率为100bit/s。通话系统按单工双向方式工作,总机放大电路设置了高频补偿网络,音控静噪门和适当的AGC电路,使话音清晰,噪音降低。
First, an overview Dispatching phone is a multi-point communication system, requiring a variety of access compatible, complex conditions. Modern computer technology and microelectronic technology have opened up a new way for the development of telecommunication science and technology. The development of program-controlled dispatching telephone has brought the dispatching telephone into a new stage. Program-controlled dispatching telephone by the election called and call two systems, the block diagram shown in Figure 1. Selection signal using frequency shift keying modulation (FSK), with eight in four (C_8 ~ 4) combination code, the signaling rate of 100bit / s. The call system works in simplex bidirectional mode. The switchboard amplifier circuit is equipped with a high-frequency compensation network, a noise control gate and an appropriate AGC circuit to make the voice clear and the noise reduced.