485星型结构，最远距离是多少？...

<p>大家好：</p><p>PC下面通过232转485转换后挂接10台门禁控制器（不是手拉手方式），如果用星型结构，最远距离能走多远？</p>

说不清.最好不要这样接,用一个485分配器吧

<p>可以走375.4765米</p>

485不是能走1200M吗

<p><font size="1">同意２楼建议</font></p>

10条线的距离之和为1200米

星的接法线的总长不要超过１２００米了！

1200M

<p>同意6楼兄弟意见</p>

<p>在1200米的基本基础上,加上一个中继器最多可以走3000多米.</p>

<p>典型距离值是1200M,但因为环境情况等各方面原因,实际到不了1200M,我最远用到过1100M</p>

<p>前一阵子看了一篇文章说485传1200米前提是传输线缆是最好的......总线上只有一台485设备.........才可能传输到1200米..........晕..........</p><p>不知道是真的还是假的????</p>

错误：485总线的通讯距离可以达到1200米.<br/>其实只是485总线结构理论上 在理想环境的前提下才有可能使得传输距离达到1200米.一般是指通讯线材优质达标,波特率9600,只有一台485设备才能使得通讯距离达到1200米,而且能通讯并不代表每次通讯都正常.所以通常485总线实际的稳定的通讯距离远远达不到1200米. 负载485设备多,线材阻抗不合乎标准,线径过细,转换器品质不良,设备防雷保护,波特率的加高等等因素都会降低通讯距离.

<p>加个485HUB分出去吧，理想的话，700米以下没有问题的</p><p></p>

干吗非要走到极限呢，想不通！

同意14楼说法！

<p>&nbsp;&nbsp;&nbsp; 大家说的都很好,485通讯距离理论上是可以达到1200米(各个分支的总和).我用过科松的分了两条线,带了23个一体机.还挺稳定的.不过刚开始出了点问题,我没有用他们配套的RS485/232转换器,很不稳定,后来又买了他们的,呵呵稳定的一腿!</p>

<span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <font color="#0000ff" size="5"><strong>RS485</strong></font></span><font color="#0000ff"><font size="5"><strong><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">总线是一种广泛应用的半双工总线，</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">RS485</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">总线是一个主站对从站的点对多点网络，</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">RS485</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">总线通过一对双绞线将现场所有的</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">RS485</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">设备以总线型结构从头到尾连接起来</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">
                                </span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">。但在实际现场应用中，很难用一条总线将所有设备连接起来，现场设备大多是星型、放射型点对多点分布。于是市场上出现了</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">485HUB</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">能将</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">RS485</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">总线能将</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">RS485</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">总线变为星型或放射型分布，即将一条</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">RS485</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">总线变为多条分叉型</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">RS485</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">总线，使</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">RS485</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">总线连接变得十分简单，将现场分散分布的远距离节点、从站与中心主站连成一可行的</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">RS485</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">总线网络。可以负荷</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">128</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">个节点，对一般工程应该可以应付了。所以节点的总线总和不超过</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">1200</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">米，本人用过</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: &quot;Times New Roman&quot;; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">JaRa</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: &quot;Times New Roman&quot;; mso-hansi-font-family: &quot;Times New Roman&quot;; mso-bidi-font-family: &quot;Times New Roman&quot;;">品牌还不错。</span></strong></font></font>

<p>专家言：用485HUB，理想下是1200M。实际最远可达800M。</p><p>公司：深圳市微耕实业有限公司<br/>网址：<a href="http://www.wiegand.com.cn">www.wiegand.com.cn</a><br/>销售：李佳玉<br/>电话：0755-82501125<br/>传真：0755-82500661<br/>手机：13148822980<br/>MSN:wgxs001@hotmail.com<br/>E-mail:wiegand26@126.com<br/></p>

<p>如果真正的是走星型，那你得选用，RS485HUB，而现在的这个设备，参数是3000米，能不能达到这个效果，主是要看这设备的好坏有关，好的厂家加了光隔后，性能真的很好。实际中的距离要根环境和干扰有关，如果按弱电布方式布线，2000米左右不成问题的，我在实际中证实过。</p>