PLC输入的线间电容引起的误动作

<p style="box-sizing: border-box; margin-top: 20px; margin-bottom: 20px; padding: 0px; border: 0px; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; font-weight: 700; margin: 0px; padding: 0px; border: 0px;"><span style="text-decoration:underline;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">PLC输入的线间电容引起的误动作</span></span></span></span></p><p style="box-sizing: border-box; margin-top: 20px; margin-bottom: 20px; padding: 0px; border: 0px; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">电缆的各导线间都存在电容，合格的电缆能把此容值限制在一定范围之内。就是合格的电缆，当电缆长度超过一定长度时，各线间的电容容值也会超过所要求的值，当把此电缆用于PLC输入时，线间电容就有可能引起PLC的误动作，会出现许多无法理解的现象。</span></span></p><p style="box-sizing: border-box; margin-top: 20px; margin-bottom: 20px; padding: 0px; border: 0px; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">主要为：</span></span></p><ul style="box-sizing: border-box; margin: 20px 30px; padding: 0px; border: 0px; counter-reset: ul_list 0; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);" class=" list-paddingleft-2"><li><p><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">明明接线正确，但PLC却没有输入；</span></span></p></li><li><p><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">PLC应该有的输入没有，而不应该有的却有，即PLC输入互相干扰。</span></span></p></li></ul><p style="box-sizing: border-box; margin-top: 20px; margin-bottom: 20px; padding: 0px; border: 0px; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">最近，在调试一PLC系统时，就出现了一种现象。MIC传感器不动作，或动作后，另一传感器（FLY）的动作影响MIC传感器，即：MIC动作时，FLY传感器一动作，MIC就变成不动作了。也就是：传感器的动作彼此影响，怀疑是电缆质量不好，线间电容不合要求造成的。直接把MIC传感器接到PLC，不使用电缆后，一切动作正常。</span></span></p><p style="box-sizing: border-box; margin-top: 20px; margin-bottom: 20px; padding: 0px; border: 0px; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">消除线间电容影响的办法：</span></span></p><p style="box-sizing: border-box; margin-top: 20px; margin-bottom: 20px; padding: 0px; border: 0px; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">（1）使用电缆芯绞合在一起的电缆；</span></span></p><p style="box-sizing: border-box; margin-top: 20px; margin-bottom: 20px; padding: 0px; border: 0px; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">（2）尽量缩短使用电缆的长度；</span></span></p><p style="box-sizing: border-box; margin-top: 20px; margin-bottom: 20px; padding: 0px; border: 0px; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">（3）把互相干扰的输入分开使用电缆；</span></span></p><p style="box-sizing: border-box; margin-top: 20px; margin-bottom: 20px; padding: 0px; border: 0px; color: rgb(34, 34, 34); font-family: &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei&quot;, &quot;WenQuanYi Micro Hei&quot;, &quot;Helvetica Neue&quot;, Arial, sans-serif; font-size: 18px; text-align: justify; text-wrap: wrap; background-color: rgb(255, 255, 255);"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; letter-spacing: 1px;"><span style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; color: rgb(64, 118, 0); --tt-darkmode-color: #407600;">（4）使用屏蔽电缆。</span></span></p><p><br/></p>