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家庭治安防护的设施很多,需要防护的除防盗以外还涉及防火、防煤气中毒等多方面。针对这些防护要求,目前流行的防护设施从简单的防盗门到复杂的电子锁、电子鼻等,可以说是品类繁多,百姿纷呈。当前流行的报警装置多采用专线进行信号传输,这样安装成本会很高,而且费时费力。最近出现一种新构思、新设计的楼宇保安网络系统,又作出显著改进。新设计方案采用数字编码,对门牌号及报警类别进行识别。数字信号经调后变音频信号,通过电源线进行传输,因此免除了架线的麻烦及费用。由于音频信号频率较低,功率也较小,所以不会对其他家电造成干扰。为防止盗贼在入室之前割断电线造成信号中断,本系统设计成查询与中断申请结合的方式。即在没有分机来的报警信号要求主机中断时,主机一方面计时作时钟显示,另一方面轮流向各分机发出查询信号。分机收到查询信号后对主机应答。应答信号为门牌号,而报警类型信号则置为“O”表示安全。若主机发出查询信号后收不到分机应答,则应判为分机损坏或电源线断
Family law and order protection of many facilities, in addition to security needs in addition to anti-theft is also involved in fire prevention, gas poisoning and many other aspects. In response to these protection requirements, the current popular protection facilities from a simple security door to a complex electronic locks, electronic nose, etc., can be said that a wide range of diverse. The current popular alarm device to use more green signal transmission, so that the installation costs will be high, but time-consuming and laborious. Recently, a new concept emerged. The newly designed building security network system also made significant improvements. The new design uses digital coding to identify the house number and alarm category. After the digital signal is adjusted to change the audio signal, transmission through the power cord, thus eliminating the hassle and overhead wiring. As the audio signal frequency is lower, the power is smaller, so it will not cause interference to other appliances. In order to prevent thieves cut off the wire before entering the room caused by signal interruption, the system designed to query and interrupt the application combination. That is, no extension to the alarm signal requires the host interrupt, the host clock on the one hand for the clock display, on the other hand turns to the extension issued a query signal. Ext after receiving the query signal to the host to answer. The answer signal is a house number, and the alarm type signal is set to “O” to indicate safety. If the host can not receive the extension after receiving the inquiry signal, it shall be judged as the extension damaged or the power cable broken