国产欧美精品区一区二区三区_日韩精品极品视频在线观看免费_国产一区二区三区乱码在线观看_国产欧美日韩在线观看精品_91精品国产麻豆国产自产在线_91麻豆精品国产91久久久久久_精品欧美一区二区三区久久久_久久99精品久久久久久三级_国产精品毛片久久久久久久_久久久精品中文字幕麻豆发布

洞察行業(yè)資訊 分享專業(yè)知識(shí)

洞察行業(yè)資訊 分享專業(yè)知識(shí)

洞察行業(yè)資訊 分享專業(yè)知識(shí)

洞察行業(yè)資訊 分享專業(yè)知識(shí)

聯(lián)系我們

  • 全國(guó)統(tǒng)一服務(wù)熱線：

    134 1039 1245
    400-996-0787
    0755-8399 9818

  • 聯(lián)系郵箱：

    sales@faxytech.com

  • 聯(lián)系地址：

    深圳市福田區(qū)華強(qiáng)北路華聯(lián)發(fā)大廈602室

3dB原則(法則) – DTX-1800/DSX2-8000 CableAnalyzer

A YouTube video explaining how this this works is also?available from here.


This is applicable to ALL test limits in the DTX CableAnalyzer where a Return Loss measurement is made.


When?the Insertion Loss is less than 3.0 dB at the frequency point where the measurement is made, then the Return Loss measurement is ignored and not uated against the selected Test Limit/Cabling Standard in the DTX CableAnalyzer.This is often referred to as the?3 dB rule.It applies to ALL cabling standards/test limits in the DTX CableAnalyzer.


On a short?link,the Insertion Loss may never reach 3.0 dB.If that were to happen, then the entire measurement would be?ignored, or as the cabling standards phrase it; “recorded for information only”.If this were to happen with your DTX CableAnalyzer, you would see an “i” appear next to the summary result for that test parameter.In LinkWare software, the result would be recorded with “N/A’.An example is shown below:


1.gif


Concern is normally caused when the result has a negative margin.In this example we see the Return Loss margin was -2.2. A?negative margin is normally associated with a FAIL, but because the entire link never exceeded 3.0 dB Insertion Loss, it is not a FAIL.


Let’s review in detail how this works by looking at another example test result.


A TIA Cat 5e Perm.Link AUTOTEST was run on a 29.0 m installed link, giving the following result:


2.gif


Looks normal – very nice margins.Let’s take a look at the Return Loss result in a little more detail:


3.gif


You will observe that?the limit line has two colors, black and red.The cabling standards do not require the cable tester manufacturer to display where the?3 dB rule is implemented to the user, only that it is implemented.However, the DTX CableAnalyzer will indicate where the 3 dB rule has been implemented by changing the color of the limit line.If the?limit line is black, it?indicates that the Insertion Loss was less than 3.0 dB.If the?limit line is red, the Insertion Loss was 3.0 dB or greater.So for this Pair 3,6 the Return Loss?is not uated below 29.3 MHz. Let’s take a quick look at the Insertion Loss for Pair 3,6:


4.gif


As you can see, the Insertion Loss reached 3.0 dB at 29.3 MHz, as previously indicated in the Return Loss Pair 3,6 graph above.


It’s an interesting rule, because if it were not in place, our margin for the above result would reduce from 10.2 dB to 9.0 dB:


5.gif


As previously mentioned, if the link is particularly short, then the Insertion Loss may never reach 3.0 dB and the entire Return Loss?result is “ignored”.Let’s take a closer look at the first example where the test result was:


6.gif


Looking at the worst case Return Loss result, we see the entire limit line is black, suggesting that the Insertion Loss for Pair?3,6 never reached 3.0 dB:


7.gif


Looking at the Insertion Loss for Pair 3,6:


8.gif


We see that the Insertion did indeed never reach 3.0 dB, so the entire measurement is not uated against the limit line (ignored) and recorded as “i” Information Only.If this result was downloaded to LinkWare Software, the report would show N/A against this measurement:


9.gif


No further action is required by the installer.This is a valid standards compliant result.


相關(guān)配件（）
偃师市| 新干县| 宜兰县| 乌海市| 凤阳县| 临汾市| 滁州市| 洛隆县| 时尚| 崇左市| 平谷区| 安丘市| 北辰区| 南汇区| 巴中市| 会理县| 德阳市| 益阳市| 龙口市| 河源市| 华阴市| 临西县| 句容市| 上思县| 元阳县| 海门市| 南京市| 南和县| 夏津县| 中方县| 兴化市| 汾西县| 禹城市| 晋城| 南阳市| 茌平县| 翁源县| 静海县| 镇沅| 金乡县| 石泉县|