英威中型PLC_赋值运算符的应用

<h4 style="overflow-wrap: break-word; margin: 0px 0px 16px; padding: 0px; font-size: 14px; line-height: 1.25; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; text-wrap: wrap; background-color: rgb(255, 255, 255);">1.1.2赋值运算符的应用</h4><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">ST语言的赋值语句 使用的是“:=”.下面我们来看看使用案例</p><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">vi_NumOfPeople := 100;<br/>vi_人数 := 100;</p><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">上面两句话的意思，其实就是将 100这个数值赋值给我们 变量中。程序运行之后，“vi_NumOfPeople”这个变量中的数值为 100，而这个变量“vi_人数”中的数值也是100.</p><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">vb_StopButton := TRUE;<br/>vb_启动按钮 := FALSE;</p><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);"><img src="/upload/image/20230621/1687340491979835.png" alt="" style="overflow-wrap: break-word; border: 0px; vertical-align: middle;"/></p><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">赋值语句顺序是 &quot;从后向前&quot;，也就是把后面变量里的 值，赋值给前面的变量。这个和数学上的等于是不一样的哈，大家注意。</p><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">再强调一遍，ST语言中“:=”赋值语句，是将 后面变量里的值，赋值给前面的变量的。顺序是“从后向前”。</p><h4 style="overflow-wrap: break-word; margin: 0px 0px 16px; padding: 0px; font-size: 14px; line-height: 1.25; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; text-wrap: wrap; background-color: rgb(255, 255, 255);">1.1.3 不同数据类型赋值需要进行强制类型转换</h4><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">如果不强制类型转换，提示效果如下<br/><img src="/upload/image/20230621/1687340491220077.png" alt="" style="overflow-wrap: break-word; border: 0px; vertical-align: middle;"/></p><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">使用强制类型转换后：<br/><img src="/upload/image/20230621/1687340491748473.png" alt="" style="overflow-wrap: break-word; border: 0px; vertical-align: middle;"/></p><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">强制类型转换的含义就是，将等式右边的数据类型和左边的数据类型统一。</p><p style="overflow-wrap: break-word; margin-top: 0px; margin-bottom: 15px; padding: 0px; color: rgb(51, 51, 51); font-family: -apple-system, BlinkMacSystemFont, &quot;Segoe UI&quot;, Helvetica, Arial, sans-serif, &quot;Apple Color Emoji&quot;, &quot;Segoe UI Emoji&quot;; font-size: 14px; text-wrap: wrap; background-color: rgb(255, 255, 255);">常用的数据类型转换格式：当前数据类型_TO_目标数据类型(变量);<br/>REAL_TO_DINT(变量B);//把 浮点型变量B 强制转换成 DINT型<br/>DINT_TO_REAL(变量C);//把 32位整型数据 强制转换成 REAL浮点型<br/>INT_TO_DINT(变量D);//把16位整型数据强制转换成32位整型数据<br/>INT_TO_REAL(变量E);//把16位整型变量强制转换成浮点型</p>