This circuit board can translate impulse signal outputted from photoelectric sensor into ascii codes and then input them into serial interface of the computer , these ascii codes are ulteriorly displayed and disposed through the cat software 该电路板可将光电传感器输出的脉冲信号转换成ascll码输入到计算机串o ，进一步通过相应的cat软件进行显示与数据处理。
For the anticounterfeiting of printings ( such as certificate ) , the existent many ways ( such as rainbow holograms ) are not available as the need for special use : anti - distortion and anti - copy . basing in the double - random - phase transform , this article puts forward a new way that two - dimensional bar code is used as anticounterfeiting label with anti - printing ? scanning and anti - damage properties . the major job are : ( 1 ) . basing in the ascii codes , numerals and alphabets are encoded and subsequently transformed into two - value bar code matrix figure . later , using amplitude - based double - random - phase transform , the enciphered gray scale figure is formed . by computer simulation ( 4f system ) and printing as well as scanning ( 20 times ) , we get the result that the gray scale figure with little miscoding rate ( 0 . 0026 ) by “ matrix expanding way ” 本文主要开展了以下三项研究工作: ( 1 ) .用自定义编码方案,将数字和字母( ascii码)转换成二值条码图;对该图形进行振幅型双随机相位加密变换,得到原信息的加密灰度图;通过4f光学系统计算机模拟和打印-扫描实验,证明本文提出的“矩阵扩展法”灰度图具有较小的误码率,对于20次打印-扫描实验,误码率不大于0 . 0026 。
According to the trend , this paper introduces the technology of database and pc ' s serial port communication , which is adopted as the technology premise of wireless surveillance control system . and it illustrates the key technologies of how to realize the wireless surveillance control system . by making full use of its possible expansibility , flexibility and pervasive applicability , as well as the serial port communication technology , scada could help to transmit batch of data effectively , extend the ascii code serial port communication processing in the mscomm components and transmit the large - scale data stream 针对这一趋势，论文在介绍了作为无线监控软件系统的技术前提的数据库技术和微型计算机串行口通信技术的基础上阐述了实现无线监控软件系统的各项关键技术，对利用数据库系统对数据结构间的关系的严格定义和约束实现系统的可扩展性、灵活性与普遍应用性、利用计算机串行口通信技术实现批量数据传输、实现了数据的有效传递、 mscomm控件中扩展ascii码的串口通信处理和大型数据流的传输等项技术作了详尽地说明，并对已完成的系统作出了评价，提出可以进一步改进的意见。
