论文部分内容阅读
为了满足流量计的串口数据和4～20mA电流信号输出形式,利用PIC16F877单片机分别设计了下位机与MODEM的通信硬件电路和软件,流量计的现场测量数据通过企业内部或公用电话网(PSTN)传输给PC机,实现远程流量计量系统。为了使系统可靠工作,主要采取了下位机的硬件和软件抗干扰措施。
基于MODEM的远程流量计量系统的设计
【摘 要】
：
为了满足流量计的串口数据和4～20mA电流信号输出形式,利用PIC16F877单片机分别设计了下位机与MODEM的通信硬件电路和软件,流量计的现场测量数据通过企业内部或公用电话网(PSTN)传输给PC机,实现远程流量计量系统。为了使系统可靠工作,主要采取了下位机的硬件和软件抗干扰措施。
【机 构】
：
西南交通大学机械工程研究所,南通纺织职业技术学院
【出 处】
：
微计算机信息
【发表日期】
：
2007年07期
其他文献
A novel cold-inducible promoter,PThCAP from Tamarix hispida,confers cold tolerance in transgenic Ara
Our previous studies have revealed that the ThCAP gene plays a vital role in transgenic Populus(P.davidiana×P.bolleana)in response to cold stress.However,t
Continuously growing populations and rapid economic development have led to the excessive use of forest resources,and the forest ecosystem is threatened.In resp
Spatial patterns nitrogen transfer models of ectomycorrhizal networks in a Mongolian scotch pine pla
Ectomycorrhizal(EM)networks provide a variety of services to plants and ecosystems include nutrient uptake and transfer,seedling survival,internal cycling of nu
Accumulation of heavy metals in stemwood of forest tree plantations fertilized with different sewage
The levels of heavy metals that accumulated in stemwood of mature trees grown for 20 years in a plantation in an abandoned peat quarry in areas that were fertil
Forest disturbance and recovery are critical ecosystem processes,but the temporal patterns of disturbance have not been studied in subtropical China.Using a tre
Degradation of atrazine and changes in soil biological indices throughout dendroremediation using po
Dendroremediation,a novel strategy for cleaning up contaminants from the environment by using special woody plant species and microbes,is a popular phytoremedia
对网络系统安全评估问题进行了研究，提出了一种评估网络系统安全的新算法。该算法基于代码分析、协议分析、脆弱性检测、认证检测等四种网络安全缺陷发现技术，多角度查找网络漏
激光CCD角度测量技术是计量与现代测试技术领域中的重要方法,具有非接触、高灵敏、高准确、高效率等特点,是当前最先进的测试技术之一。通过对面阵CCD和线阵CCD的特性分析以
本文通过分析分布式拒绝服务攻击DDoS原理和攻击方法，给出了一种防御DDoS攻击的算法。