PLC信号衰减问题处理

<p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(1)从PLC主机至I/O站的信号最大衰减值为35dB。因此，电缆敷设前应仔细规划，画出电缆敷设图，尽量缩短电缆长度(长度每增加1km，信号衰减0.8dB)；尽量少用分支器(每个分支器信号衰减14dB)和电缆接头(每个电缆接头信号衰减1dB)。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(2)通信电缆最好采用单总线方式敷设，即由统一的通信干线通过分支器接I/O站，而不是呈星状放射状敷设。PLC主机左右两边的I/O站数及传输距离应尽可能一致，这样能保证一个较好的网络阻抗匹配。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(3)分支器应尽可能靠近I/O站，以减少干扰。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(4)通信电缆末端应接75Ω电阻的BNC电缆终端器，与各I/O柜相连接，将电缆由I/O柜拆下时，带75Ω电阻的终端头应连在电缆网络的一头，以保持良好的匹配。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(5)通信电缆与高压电缆间距至少应保证40cm/kV；必须与高压电缆交叉时，必须垂直交叉。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(6)通信电缆应避免与交流电源线平行敷设，以减少交流电源对通信的干扰。同理，通信电缆应尽量避开大电机、电焊机、大电感器等设备。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(7)通信电缆敷设要避开高温及易受化学腐蚀的地区。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(8)电缆敷设时要按0.05%/℃留有余地，以满足热胀冷缩的要求。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(9)所有电缆接头，分支器等均应连接紧密，用螺钉紧固。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p style="margin: 0px 10px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important; font-size: 15px; color: rgb(63, 63, 63);">(10)剥削电缆外皮时，切忌损坏屏蔽层，切断金属铂与绝缘体时，一定要用剥线钳，切忌刻伤损坏中心导线。</span></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; outline: 0px; max-width: 100%; clear: both; min-height: 1em; font-family: system-ui, -apple-system, BlinkMacSystemFont, &quot;Helvetica Neue&quot;, &quot;PingFang SC&quot;, &quot;Hiragino Sans GB&quot;, &quot;Microsoft YaHei UI&quot;, &quot;Microsoft YaHei&quot;, Arial, sans-serif; font-size: 17px; letter-spacing: 0.544px; text-align: justify; text-wrap: wrap; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); box-sizing: border-box !important; overflow-wrap: break-word !important;"><br/></p><p><section><section><section><section><section><section><section><section><span style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">3</span>.</section><section><br/></section></section></section></section><section><strong style="margin: 0px; padding: 0px; outline: 0px; max-width: 100%; box-sizing: border-box !important; overflow-wrap: break-word !important;">系统接地问题的讨论</strong></section></section></section></section></section></p><p><br/></p>