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随着19世纪中期电报机的出现,人们就开始在地球上织起了金属网。现在,如果没有了大量的电线和电缆,简直就不可想象。看来这个观念已是深入人心,不可取代了。消防安全系统也是如此,在这一领域让人们接受无线装置并非易事,这要有一个缓慢的过程,尽管目前可以说使用有线系统的负面因素多于对无线系统的悲观程度。消防安全系统使用电缆的明显不足之处可分为以下几类:(1)设计难度加大,增加接头数量和电源线及信号线的总长度。(2)电线长容易产生干扰,因此在安全系统中容易出故障。(3)因为铜涨价,而且对电缆抗危险的稳定性要
With the advent of telegraphs in the mid-19th century, people began to weave metal meshes on the earth. Now, it would be unthinkable without a lot of wires and cables. It seems that this concept is deeply rooted and irreplaceable. The same is true for fire safety systems, and getting wireless devices to work in this area is not an easy task. It is a slow process, although there are currently more downsides to using wired systems than to pessimistic wireless systems. Fire safety system using the obvious shortcomings of the cable can be divided into the following categories: (1) design more difficult to increase the number of connectors and power lines and signal lines of the total length. (2) Cable length is prone to interference, so easy to fail in the safety system. (3) because of copper prices, but also to the stability of the cable to be dangerous