普通传真机以明文通信的方式通过有线电话网实现了远距离的复印,但现代科学技术的发展对传真的要求越来越高,普通传真将不能适应特殊环境的需要,因此,一些特殊的传真通信应运而生。下面简单 Ordinary facsimile machines realize the long distance photocopying through the wired telephone network in the mode of clear text communication. However, the development of modern science and technology requires higher and higher facsimile numbers, and ordinary facsimiles can not meet the needs of special environments. Therefore, some special facsimiles Communication came into being. The following simple