PLC控制与传统的继电器控制有哪些不同点?

<p class="MsoNormal"><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">1</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">）组成器件不同</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">&nbsp;&nbsp;</span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p><p class="MsoNormal"><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">真实</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">—</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">虚拟，硬件</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">—</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">软件（</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">PLC</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">内部存储单元中的一位，可称为</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">“</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">软继电器</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">”</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">）</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p><p class="MsoNormal" style="text-indent:15.7500pt;mso-char-indent-count:1.5000;"><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">2</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">）触点情况不同</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">&nbsp;&nbsp;</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p><p class="MsoNormal"><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">结构：硬件</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">—</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">软件（由存储器中相应位的状态</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">1</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">或</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">0</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">来决定的</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">,</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">可称为</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">“</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">软触点</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">”</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">）</font></span><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p><p class="MsoNormal"><span style="mso-spacerun:'yes';font-family:'Times New Roman';font-size:10.5000pt;mso-font-kerning:1.0000pt;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="mso-spacerun:'yes';font-family:宋体;font-size:10.5000pt;mso-font-kerning:1.0000pt;"><font face="宋体">数量：有限</font></s