zh-cnGoodspeed Rss1Tue, 07 Oct 2008 22:17:26 GMTWed, 09 Jan 2008 09:37:04 GMThttp://blog.cechinamag.com/mengxy/62716/message.aspx<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 150%"><span lang="EN-US" style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">1</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">．系统概述<span lang="EN-US"><?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">现场总线技术是</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">20</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">世纪</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">80</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">年代兴起的集控制技术、仪表技术和计算机网络技术为一体的先进的工业控制技术，其组成的系统具有可靠性高、维护性好、总线协议开放等特点。在现有的各种现场总线标准中</span><span lang="EN-US" style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">PROFIBUS</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">现场总线是一种比较流行的一种现场总线标准。</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">随着现代工业的不断发展，对生产过程的控制提出更高的要求，其中</span><span style="FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">应用于现场级高速数据传输，</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">实现现场级设备数字化，且</span><span style="FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">具有较高的实时性的</span><span lang="EN-US">PROFIBUS-DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">是市场占有率绝对领先的总线技术。</span><span lang="EN-US" style="mso-font-kerning: 0pt">PROFIBUS-DP</span><span style="FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">智能从站的开发</span><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-no-proof: yes">就是针对现场的测量控制设备微机化，并使多个从站之间以及与远程监控计算机之间，实现数据传输与信息交换，</span><span style="FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从而形成基于计算机的控制系统之间的一种全数字化、双向、多站的底层通讯系统。</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">由于</span><span lang="EN-US" style="mso-hansi-font-family: 宋体">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">现场总线具有很强的互可操作性和替换性，只要是支持</span><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">协议的现场总线设备，均可方便地挂接在</span><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">的总线上。西门子提供了一种</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从站开发的协议专用芯片</span><span lang="EN-US">(ASIC)SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">。本文就是介绍这种基于西门子</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">的</span><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">－</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从站的实现方法。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 150%"><span lang="EN-US" style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">2</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">．系统构成<span lang="EN-US"><span style="mso-spacerun: yes">&nbsp; </span><span style="COLOR: black"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span></span></span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 150%; mso-char-indent-count: 2.0"><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">－</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">配置成</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">单主站系统，</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">使用单一的总线存取协议，</span><span lang="EN-US">CP342-5</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">作为</span><span lang="EN-US">PROFIBUS </span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">总线上</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">主站，铂电阻温度采集智能从站装置作为</span><span lang="EN-US"> PROFIBUS </span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">总线上的</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从站，它们之间通信基于主</span><span lang="EN-US">-</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从原理，</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">主站周期地读取从站的输入信息并周期地向从站发送输出信息，</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">只有当主站请求时总线上的</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从站才可能活动。从站装置通过多路</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">温度采集电路实现外部温度的测量，选用</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">Pt100</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">测温范围为</span><span lang="EN-US">0</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">～</span><span lang="EN-US">850</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-bidi-font-family: 宋体">℃</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">。如图</span><span lang="EN-US">1</span><span style="COLOR: black; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">系统</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">框图所示。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; mso-char-indent-count: 2.0"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span lang="EN-US"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span lang="EN-US"><?xml:namespace prefix = v ns = "urn:schemas-microsoft-com:vml" /><v:shapetype id=_x0000_t75 stroked="f" filled="f" path="m@4@5l@4@11@9@11@9@5xe" o:preferrelative="t" o:spt="75" coordsize="21600,21600"><v:stroke joinstyle="miter"></v:stroke><v:formulas><v:f eqn="if lineDrawn pixelLineWidth 0"></v:f><v:f eqn="sum @0 1 0"></v:f><v:f eqn="sum 0 0 @1"></v:f><v:f eqn="prod @2 1 2"></v:f><v:f eqn="prod @3 21600 pixelWidth"></v:f><v:f eqn="prod @3 21600 pixelHeight"></v:f><v:f eqn="sum @0 0 1"></v:f><v:f eqn="prod @6 1 2"></v:f><v:f eqn="prod @7 21600 pixelWidth"></v:f><v:f eqn="sum @8 21600 0"></v:f><v:f eqn="prod @7 21600 pixelHeight"></v:f><v:f eqn="sum @10 21600 0"></v:f></v:formulas><v:path o:connecttype="rect" gradientshapeok="t" o:extrusionok="f"></v:path><o:lock aspectratio="t" v:ext="edit"></o:lock></v:shapetype><v:shape id=_x0000_i1025 style="WIDTH: 230.25pt; HEIGHT: 216.75pt" o:ole="" type="#_x0000_t75"><v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image001.emz"></v:imagedata></v:shape></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">如图</span><span lang="EN-US">1</span><span style="COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">系统</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">框图</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24.1pt; LINE-HEIGHT: 150%"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">该从站在上电后，它的的启动顺序为：设置从站地址－诊断请求－参数化－组态－诊断请求－数据交换，它的工作机制可以用一状态机表示，如图</span><span lang="EN-US">2</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">所示。状态机描述站在不同的工作状态以及各种状态之间的转换关系。在上电状态时，从中可以接收来自二类主站的设置从站地址报文，之后期望一个组态化报文或等待参数化报文，排斥其他报文，此时通信不能进行。当参数化与配置经诊断后正确，从站进入数据交换状态，接收主站请求后，以高优先级的诊断报文作为应答。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><b style="mso-bidi-font-weight: normal"><span lang="EN-US" style="COLOR: black; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体"><o:p>&nbsp;</o:p></span></b></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center" align="center"><span lang="EN-US"><v:shape id=_x0000_i1026 style="WIDTH: 220.5pt; HEIGHT: 235.5pt" o:ole="" type="#_x0000_t75"><v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image003.wmz"></v:imagedata></v:shape></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">图</span><span lang="EN-US">2 </span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从站状态机模型</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="mso-font-kerning: 0pt"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="mso-font-kerning: 0pt"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">3</span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">．硬件设计<span lang="EN-US"><o:p></o:p></span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><span style="FONT-FAMILY: 宋体">目前开发<span lang="EN-US">DP</span>从站最常用的<span lang="EN-US">ASIC</span>是<span lang="EN-US">Siemens</span>公司生产的<span lang="EN-US">SPC3</span>，<span lang="EN-US">SPC3</span>可独立完成全部<span lang="EN-US">PROFIBUS-DP</span>通信功能，这样可加速通信协议的执行，但<span lang="EN-US">SPC3</span>不能单独使用，需要微控制器对之控制。</span><span lang="EN-US" style="COLOR: red"><o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 150%; mso-char-indent-count: 2.0"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">设计上采用了</span><span lang="EN-US">SIEMENS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">公司提供的软件包</span><span lang="EN-US">DPS2</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，利用它可以方便的对</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">初始化。包括设置</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">允许的中断、写入从站识别号和地址、设置</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">方式寄存器、设置诊断缓冲区、参数缓冲区、配置缓冲区、地址缓冲区、初始长度，并根据以上初始值求出各个缓冲区的指针及辅助缓冲区的指针，根据传输的数据长度，确定输入缓冲区，输出缓冲区及指针。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 150%; mso-char-indent-count: 2.0"><span lang="EN-US">AT89C52</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">不参与</span><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">－</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从站状态机的运行，它的主要任务就是根据</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">产生的中断，对</span><span lang="EN-US">SP3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">接收到的主站发出输出数据转存，按照主站的要求将处理后的温度数据通过</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">发送到主站。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 150%; mso-char-indent-count: 2.0"><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">从站设计在功能上分为符合</span><span lang="EN-US">PROFIBUS-DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">协议的通讯</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">主从站通讯设计和热电阻温度采集电路的设计，相应的在从站硬件结构上分为</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体; mso-ascii-font-family: 'Times New Roman'">硬件设<span style="COLOR: black">计主要</span></span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">包括处理器系统接口电路和铂电阻温度采集电路。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 10pt; LINE-HEIGHT: 150%; mso-outline-level: 1"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">主从通讯电路主要由协议芯片</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">、</span><span lang="EN-US">89C52</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">微处理器、</span><span lang="EN-US">32K</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">扩展</span><span lang="EN-US">RAM</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">、译码器电路、用于复位的硬件看门狗</span><span lang="EN-US">MAX705</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">电路实现；热电阻温度采集电路主要由</span><span lang="EN-US">89C52</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">微处理器、</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">A/D</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">转换器</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">7109</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">和多路模拟开关</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">CD4051</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">实现</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">。</span><span lang="EN-US">89C52</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">单片机作为中央处理器，负责将现场采集的数据进行处理、分析和分类，然后通过</span><span lang="EN-US">SP3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">传到</span><span lang="EN-US">PROFIBUS-DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">总线上去，同时监测</span><span lang="EN-US">SP3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，接收</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">主站传过来的指令和数据，并进行相应的操作。如图</span><span lang="EN-US">3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US"><v:shape id=_x0000_i1027 style="WIDTH: 430.5pt; HEIGHT: 159.75pt" o:ole="" type="#_x0000_t75"><v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image005.emz"></v:imagedata></v:shape></span><span lang="EN-US" style="FONT-FAMILY: 宋体"><o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">图</span><span lang="EN-US">3 </span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从站设计原理框图</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">3</span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">．<span lang="EN-US">1</span>处理器系统接口电路<span lang="EN-US"><o:p></o:p></span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 150%; mso-char-indent-count: 2.0"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">图</span><span lang="EN-US">4 <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /><st1:chmetcnv w:st="on" TCSC="0" NumberType="1" Negative="False" HasSpace="False" SourceValue="89" UnitName="C">89C</st1:chmetcnv>52</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">与</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">接口电路。它通过</span><span lang="EN-US">16</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">位地址线和</span><span lang="EN-US">8</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">位数据线进行数据交换，外部扩展了程序存储器（</span><span lang="EN-US">EPROM</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）和数据存储器（</span><span lang="EN-US">RAM</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: Arial; mso-ascii-font-family: 'Times New Roman'">专用芯片，</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">可独立完成全部</span><span lang="EN-US">PROFIBUS-DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">通信功能，</span><st1:chmetcnv w:st="on" TCSC="0" NumberType="1" Negative="False" HasSpace="False" SourceValue="89" UnitName="C"><span lang="EN-US">89C</span></st1:chmetcnv><span lang="EN-US">52</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">完成对协议芯片的初始化、数据的发送和接收。</span> <span lang="EN-US" style="COLOR: #ff6600"><o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center" align="center"><span lang="EN-US"><v:shape id=_x0000_i1028 style="WIDTH: 243pt; HEIGHT: 141.75pt" o:ole="" type="#_x0000_t75"><v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image007.emz" cropleft="-103f" cropbottom="2905f"></v:imagedata></v:shape></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">图</span><span lang="EN-US">4 <span style="mso-spacerun: yes">&nbsp;</span>89C52</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">与</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">接口电路</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">3</span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">．<span lang="EN-US">2 </span>铂电阻温度采集电路<span lang="EN-US"><o:p></o:p></span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 150%; mso-char-indent-count: 2.0"><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">如图</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">5</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">。本</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">铂电阻温度采集电路</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，它无需恒流源、放大电路和零点迁移电路，不易引入温漂，受电流源波动影响较小。在多路测量中，多个铂热传感器共用一个</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">A/D</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">转换器</span><span lang="EN-US" style="LINE-HEIGHT: 150%; mso-bidi-font-size: 10.5pt">7109</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，由多路模拟开关切换完成多路测量。</span><span lang="EN-US">A/D</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">转换器</span><span lang="EN-US">ICL7109</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，是一种高精度、低噪声、低温漂双积分</span><span lang="EN-US">A/D</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">转换器，</span><span lang="EN-US">12</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">位精度。由于</span><span lang="EN-US">ICL7109</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">输出二进制信号码，且低</span><span lang="EN-US">8</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">位和高</span><span lang="EN-US">8</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">位分时输出，因此容易和各种</span><span lang="EN-US">8</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">位微处理器直接接口。</span><span lang="EN-US">ICL7109</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">有</span><span lang="EN-US">2</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">个差分输入端和</span><span lang="EN-US">2</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">个差分参考电压输入端，将</span><span lang="EN-US">STATUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">线与</span><st1:chmetcnv w:st="on" TCSC="0" NumberType="1" Negative="False" HasSpace="False" SourceValue="89" UnitName="C"><span lang="EN-US">89C</span></st1:chmetcnv><span lang="EN-US">52</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">的</span><span lang="EN-US"><span style="POSITION: relative; TOP: 3pt; mso-text-raise: -3.0pt"><v:shape id=_x0000_i1029 style="WIDTH: 30pt; HEIGHT: 17.25pt" o:ole="" type="#_x0000_t75"> <v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image009.wmz"></v:imagedata></v:shape></span></span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">相联，这样完成一次转换就向处理器发一次中断申请。在中断服务中</span><span lang="EN-US">12</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">位数据分两次读取，分别用</span><span lang="EN-US"><span style="POSITION: relative; TOP: 3pt; mso-text-raise: -3.0pt"><v:shape id=_x0000_i1030 style="WIDTH: 36.75pt; HEIGHT: 17.25pt" o:ole="" type="#_x0000_t75"> <v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image011.wmz"></v:imagedata></v:shape></span></span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">和</span><span lang="EN-US"><span style="POSITION: relative; TOP: 3pt; mso-text-raise: -3.0pt"><v:shape id=_x0000_i1031 style="WIDTH: 35.25pt; HEIGHT: 17.25pt" o:ole="" type="#_x0000_t75"> <v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image013.wmz"></v:imagedata></v:shape></span></span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">控制。并同时得到极性和溢出标志。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center" align="center"><span lang="EN-US"><v:shape id=_x0000_i1032 style="WIDTH: 222.75pt; HEIGHT: 138.75pt" o:ole="" type="#_x0000_t75"><v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image015.emz"></v:imagedata></v:shape></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: center" align="center"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">图</span><span lang="EN-US">5 </span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">多路测温系统框图</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 150%; mso-char-indent-count: 2.0"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">系统采用多路四线制的接线，</span><span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">采用的比例法测温方案，</span><span lang="EN-US">K1</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">、</span><span lang="EN-US">K2</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">、</span><span lang="EN-US">K3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">是多路模拟开关（</span><span lang="EN-US">CD4051</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">），</span><span lang="EN-US">K1</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">用来切换电流，</span><span lang="EN-US">K2</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">、</span><span lang="EN-US">K3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">用来切换输入的差分电压。由于</span><span lang="EN-US">7109</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">具有高输入阻抗，</span><span lang="EN-US">B</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">、</span><span lang="EN-US">C</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">两段长引线造成的压降可以忽略不计，流过铂电阻</span><span lang="EN-US">Rx</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">和参考电阻</span><span lang="EN-US">Rr</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">的电流可认为相等，虽然模拟开关的导通电阻和相应的长引线的引入会改变流过</span><span lang="EN-US">Rx</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">和</span><span lang="EN-US">Rr</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">的电流，但差分输入电压保持不变，由比率法公式得到的电阻比值关系</span><span lang="EN-US" style="COLOR: #ff6600"><span style="POSITION: relative; TOP: 6pt; mso-text-raise: -6.0pt"><v:shape id=_x0000_i1033 style="WIDTH: 87pt; HEIGHT: 18pt" o:ole="" type="#_x0000_t75"> <v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image017.wmz"></v:imagedata></v:shape></span></span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">也不变，其中</span><span lang="EN-US">N</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">是</span><span lang="EN-US">A/D</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">采样值的十进制数。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 150%"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体"><o:p>&nbsp;</o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">4</span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">．软件设计<span lang="EN-US"><o:p></o:p></span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">从站的软件设计包括上下位机两部分。下位机软件包括通信主程序和用户程序编写，固化在</span><span lang="EN-US">89C52</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">中，实现与</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">主站的通信和铂电阻温度信号采集。上位机软件主要是在</span><span lang="EN-US">STEP-7</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">的</span><span lang="EN-US">PLC</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">编程，实现铂电阻温度检测装置的通信和温度数据的转换存储；组态软件</span><span lang="EN-US">WINCC</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">人机界面设计，实现对温度进行实时监测和历史数据查询，历史报表等。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">下面就</span><span lang="EN-US">DPS2</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">中的</span><span lang="EN-US">userspc3.c</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">模块用户程序编写做简单介绍：</span></p> <p class="MsoNormal" style="MARGIN: 7.8pt 0cm; TEXT-ALIGN: center; mso-para-margin-top: .5gd; mso-para-margin-right: 0cm; mso-para-margin-bottom: .5gd; mso-para-margin-left: 0cm" align="center"><span style="FONT-FAMILY: 黑体; mso-bidi-font-size: 10.5pt">表<span lang="EN-US">1</span>源程序组成<span lang="EN-US"><o:p></o:p></span></span></p> <table class="MsoNormalTable" style="BORDER-RIGHT: medium none; BORDER-TOP: medium none; BORDER-LEFT: medium none; BORDER-BOTTOM: medium none; BORDER-COLLAPSE: collapse; mso-border-alt: solid windowtext .5pt; mso-yfti-tbllook: 480; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt; mso-border-insideh: .5pt solid windowtext; mso-border-insidev: .5pt solid windowtext" cellSpacing="0" cellPadding="0" border="1"> <tbody> <tr style="mso-yfti-irow: 0; mso-yfti-firstrow: yes"> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 1pt solid; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">源程序模块</span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 1pt solid; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: windowtext 1pt solid; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.25pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">模块功能</span></p></td></tr> <tr style="mso-yfti-irow: 1"> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US">userspc3.c</span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">主函数</span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.25pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">启动、输入</span><span lang="EN-US">/</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">输出、诊断</span></p></td></tr> <tr style="mso-yfti-irow: 2"> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US">intspc3.c</span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">中断程序块</span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.25pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">参数设置及组态</span></p></td></tr> <tr style="mso-yfti-irow: 3"> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US">dps2spc3.c</span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">帮助功能块</span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.25pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">计算缓冲组态</span></p></td></tr> <tr style="mso-yfti-irow: 4; mso-yfti-lastrow: yes"> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: windowtext 1pt solid; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US">dps2user.h</span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.2pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">宏与定义</span></p></td> <td style="BORDER-RIGHT: windowtext 1pt solid; PADDING-RIGHT: 5.4pt; BORDER-TOP: #ece9d8; PADDING-LEFT: 5.4pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: #ece9d8; WIDTH: 147.25pt; PADDING-TOP: 0cm; BORDER-BOTTOM: windowtext 1pt solid; BACKGROUND-COLOR: transparent; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt" vAlign="top" width="196"> <p class="MsoBodyText" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">便于用户对</span><span lang="EN-US">ASIC</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">寄存器操作</span></p></td></tr></tbody></table> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 16.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">主要</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">程序如下：</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">1</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）复位</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">：</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">PRO_RUN=0;<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;</span>/*</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">程序状态</span><span lang="EN-US">*/</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 15.75pt; mso-char-indent-count: 1.5"><span lang="EN-US"><span style="mso-spacerun: yes">&nbsp;</span>address=*(&amp;OWN_ADDRESS);</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">SPC3_RESET = SPC3_RESET_SET;<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;</span><span style="mso-spacerun: yes">&nbsp;</span>/*</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">强制复位引脚</span><span lang="EN-US"> */</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">for(i = 0; i&lt;100 ; i++);</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">SPC3_RESET = !SPC3_RESET_SET;</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">HW_WATCHDOG_TRIGGER = 1;<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>/*</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">触发硬件看门狗</span><span lang="EN-US">*/</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; mso-char-indent-count: 2.0"><span lang="EN-US">HW_WATCHDOG_TRIGGER = 0;</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">2</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）外部数据处理程序</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt">float xdata<span style="mso-spacerun: yes">&nbsp; </span>f[8] _at_ 0xD000;<span style="mso-spacerun: yes">&nbsp;&nbsp; </span><o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt">sbit p10=P1^0;<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt">sbit p11=P1^1;<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt">sbit p12=P1^2;<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">for(i=1;i&lt;9;i++)<span style="mso-tab-count: 1">&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="mso-spacerun: yes">&nbsp;</span>/*</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">实现</span><span lang="EN-US">8</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">通道铂电阻温度检测</span><span lang="EN-US">*/</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">{</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">switch(i)</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US"><span style="mso-spacerun: yes">&nbsp;&nbsp; </span>{</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">case 1:</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">write(0x11);<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="mso-spacerun: yes">&nbsp;</span><span style="mso-spacerun: yes">&nbsp;</span><span style="mso-spacerun: yes">&nbsp;</span>/* ICL7109</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">的写函数</span><span lang="EN-US">*/</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">write(0x64);</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">p10=0;p11=0;p12=0;<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="mso-spacerun: yes">&nbsp;</span>/* </span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">控制多路开关</span><span lang="EN-US">1</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，</span><span lang="EN-US">2</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">，</span><span lang="EN-US">3*/</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">rt</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">＝</span><span lang="EN-US">read</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">（</span><span lang="EN-US">i</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）</span><span lang="EN-US"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span>/* ICL7109</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">的读函数</span><span lang="EN-US">*/</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">f(1)=wendu()<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp; </span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">break</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">；</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">case2:</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">…….</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">f(2)=wendu()</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">；</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">break</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">；</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">case8:</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">…… </span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">f(8)=wendu()<span style="mso-spacerun: yes">&nbsp; </span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">break;<span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">}</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 15.75pt; mso-char-indent-count: 1.5"><span lang="EN-US"><span style="mso-spacerun: yes">&nbsp;</span>3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）温度非线性校正子程序</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">float wendu()</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">{</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">t=(rt-100)/0.37;</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">do{</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">rtt=100+t*(0.390802-0.0000580195*t);</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">t=t+(rt-rtt)/0.37;</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">}</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">while((rt-rtt)&gt;0.005||(rtt-rt)&gt;0.005);</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">return(t);</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US">}</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt">4</span><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 16.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）发送温度采样值至主站</span><span lang="EN-US" style="mso-bidi-font-size: 16.0pt"><o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span style="FONT-FAMILY: 宋体; mso-bidi-font-size: 16.0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">通过指针函数将从站数据传送至主站</span><span lang="EN-US" style="mso-bidi-font-size: 16.0pt"><o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 39.7pt; mso-char-indent-count: 3.78"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt">*(((UBYTE SPC3_PTR_ATTR*) user_input_buffer_ptr) + 0)<span style="mso-spacerun: yes">&nbsp; </span><span style="mso-spacerun: yes">&nbsp;</span>=<span style="mso-spacerun: yes">&nbsp; </span>XBYTE[0xD000];<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt"><span style="mso-spacerun: yes">&nbsp;&nbsp; </span>*(((UBYTE SPC3_PTR_ATTR*) user_input_buffer_ptr) + 1)<span style="mso-spacerun: yes">&nbsp;&nbsp; </span>=<span style="mso-spacerun: yes">&nbsp; </span>XBYTE[0xD001];<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt"><span style="mso-spacerun: yes">&nbsp;&nbsp; </span>*(((UBYTE SPC3_PTR_ATTR*) user_input_buffer_ptr) + 2)<span style="mso-spacerun: yes">&nbsp;&nbsp; </span>=<span style="mso-spacerun: yes">&nbsp; </span>XBYTE[0xD002];<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt"><span style="mso-spacerun: yes">&nbsp;&nbsp; </span>*(((UBYTE SPC3_PTR_ATTR*) user_input_buffer_ptr) + 3)<span style="mso-spacerun: yes">&nbsp;&nbsp; </span>=<span style="mso-spacerun: yes">&nbsp; </span>XBYTE[0xD003];<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 39.7pt; mso-char-indent-count: 3.78"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt">*(((UBYTE SPC3_PTR_ATTR*) user_input_buffer_ptr) + 4)<span style="mso-spacerun: yes">&nbsp;&nbsp; </span>=<span style="mso-spacerun: yes">&nbsp; </span>XBYTE[0xD004];<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt"><span style="mso-spacerun: yes">&nbsp;&nbsp; </span>*(((UBYTE SPC3_PTR_ATTR*) user_input_buffer_ptr) + 5)<span style="mso-spacerun: yes">&nbsp;&nbsp; </span>=<span style="mso-spacerun: yes">&nbsp; </span>XBYTE[0xD005];<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt"><span style="mso-spacerun: yes">&nbsp;&nbsp; </span>*(((UBYTE SPC3_PTR_ATTR*) user_input_buffer_ptr) + 6)<span style="mso-spacerun: yes">&nbsp;&nbsp; </span>=<span style="mso-spacerun: yes">&nbsp; </span>XBYTE[0xD006];<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt"><span lang="EN-US" style="mso-bidi-font-size: 16.0pt"><span style="mso-spacerun: yes">&nbsp;&nbsp; </span>*(((UBYTE SPC3_PTR_ATTR*) user_input_buffer_ptr) + 7)<span style="mso-spacerun: yes">&nbsp;&nbsp; </span>=<span style="mso-spacerun: yes">&nbsp; </span>XBYTE[0xD007];<o:p></o:p></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; LINE-HEIGHT: 150%; mso-char-indent-count: 2.0"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">用户的主要工作在于用户主程序的设计，包括外部信号处理程序，从站数据的发送，接收来自主站的数据以及诊断事务的处理部分的程序。主程序框图如图</span><span lang="EN-US">6</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">所示。只要熟悉</span><span lang="EN-US">SPC3</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">工作状态机制，</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">接口程序并不难编写。</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span lang="EN-US"><v:shape id=_x0000_i1034 style="WIDTH: 135pt; HEIGHT: 182.25pt" o:ole="" type="#_x0000_t75"><v:imagedata o:title="" src="file:///C:\DOCUME~1\mengxy\LOCALS~1\Temp\msohtml1\01\clip_image019.emz"></v:imagedata></v:shape></span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 21pt; TEXT-ALIGN: center; mso-char-indent-count: 2.0" align="center"><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">图</span><span lang="EN-US">6 </span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">主程序框图</span></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 150%"><b style="mso-bidi-font-weight: normal"><span lang="EN-US" style="COLOR: black; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">5</span></b><b style="mso-bidi-font-weight: normal"><span style="COLOR: black; LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 宋体">．心得体会<span lang="EN-US"><o:p></o:p></span></span></b></p> <p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 150%"><span lang="EN-US"><span style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp; </span></span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">本文将工业铂热电阻测温较常用的比率方法与</span><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">－</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">技术相结合，开发出一种温度采集智能从站，由于该系统的</span><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">－</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">接口设计的通用性，可以根据具体情况设计不同的信号采集部分，开发出适用于不同要求的智能从站，这必将大大减短开发周期，从而具有很大的扩展空间。根据本方案开发的从站完全符合</span><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">标准，在实际应用中将从站通过</span><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">－</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">总线与一类主站</span><span lang="EN-US">PLC</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">相连，在二类主站（</span><span lang="EN-US">PC</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">）上使用</span><span lang="EN-US">Step7</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">软件采集温度信号，并通过</span><span lang="EN-US">WINCC</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">组态软件画面显示出来。实际运行中稳定可靠，该从站和其他现场总线设备共同挂接在</span><span lang="EN-US">PROFIBUS</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">－</span><span lang="EN-US">DP</span><span style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">上，从而实现了整个控制过程</span><span style="FONT-FAMILY: 宋体; mso-font-kerning: 0pt; mso-hansi-font-family: 'Times New Roman'; mso-ascii-font-family: 'Times New Roman'">的分散化、省配线化及标准化的要求。</span></p>http://blog.cechinamag.com/mengxy/62716/message.aspx 现场总线