青青青在线观看视频免费播放-青青青在线观看国产精品-青青青伊人-青青青亚洲精品国产-青青青网-青青青爽在线视频观看大全

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

4db原則（法則）-英文原文 -福祿克DSX2-8000/DTX-1800

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


This is applicable to the following cabling standards only:


ISO/IEC 11801

EN 50173

Aus/NZ

JIS


When?the Insertion Loss is less than 4.0 dB at the frequency point where the measurement is made, then the measurement is ignored and not uated against the selected Test Limit/Cabling Standard in the DTX CableAnalyzer. This is often referred to as the 4 dB rule. It is not applied in the North American TIA Cabling Standards. Only certain test parameters and configurations will have the 4 dB rule. The tables below indicate which link? definitions and test parameters have the 4 dB rule applied to them. As an aid, the other rules are also listed.


1.png

2.png


On a?short link, the Insertion Loss may never reach 4.0 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:


3.gif


Concern is normally caused when the result has a negative margin. In this example we see the NEXT margin was -9.7 dB. A?negative margin is normally associated with a FAIL, but because the entire link never exceeded 4.0 dB Insertion Loss, it’s not a FAIL. Further?confusion lies in that the North American ANSI/TIA/-568-C.0 cabling standard does not have this 4 dB rule. If you were to test the same link above?with the same DTX CableAnalyzer, but using the North American Standard TIA Cat 5e Perm. Link, your result would be a FAIL.


4.gif


Please make sure you?have agreed in a Test Limit, in writing, before the project starts.


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


An ISO11801 PL Max Class D AUTOTEST was run on a short 6.0 m installed link, giving the following result:


5.gif


Looks normal. Let’s take a look at the NEXT result in a little more detail:


6.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 4 dB rule is implemented to the user, only that it is implemented. However, the DTX CableAnalyzer will indicate where the 4 dB rule has been implemented by changing the color of the limit line. If the?limit line is black,?the Insertion Loss was less than 4.0 dB. If?the limit line is red,?the Insertion Loss was 4.0 dB or greater. So for this Pair 1,2-4,5 the NEXT is not uated below 84.8 MHz. Let’s take a quick look at the Insertion Loss for Pair 4,5:


7.gif


As you can see, the Insertion Loss reached 4.0 dB at 84.8 MHz, as previously indicated in the NEXT Pair 1,2-4,5 graph above. NEXT contains two pairs. So which Insertion Loss pair do we use to implement the 4 dB rule? The disturbed pair is used for uation purposes. So if the worst case NEXT Pair was 1,2-7,8 then the?DTX CableAnalyzer would use the Insertion Loss values from Pair 7,8 to determine where the 4 dB rule is implemented.


As previously mentioned, if the link is particularly short, then the Insertion Loss may never reach 4.0 dB and the entire NEXT result is “ignored”. Let’s take a closer look at the first example where the test result was:


8.gif


Looking at the worst case NEXT result, we see the entire limit line is black, suggesting that the Insertion Loss for Pair 4,5 never reached 4.0 dB:


9.gif


Looking at the Insertion Loss for Pair 4,5:


10.gif


We see that the Insertion did indeed never reach 4.0 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:


11.gif


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

相關(guān)配件（）
主站蜘蛛池模板： 国产成人91高清精品免费| 精品日韩一区二区三区| 亚洲天堂色视频| 成人福利免费在线观看| 国产亚洲福利精品一区| 五月色婷婷久久综合| 九哥草逼网| 国产欧美日韩免费一区二区 | 亚洲精品卡1卡二卡3卡四卡| 好奇害死猫在线观看| 超级乱淫 不详| 亚洲精品第五页中文字幕| 国产激情在线| 精品免费久久久久久成人影院| 2012在线观看免费视频大全 | 国产精品日韩欧美在线 | 国产传媒在线播放| 免费亚洲一区| 欧美国产日韩在线播放 | 国产精品视频免费一区二区三区| 91制片厂制作果冻传媒2021| 无码11久岁箩筣| 亚洲嫩模吧粉嫩粉嫩冒白浆| 久久青青草原综合伊人| xxxxxx日本处大片免费看| 强插美女| 欧美成人免费tv在线播放| 日产免费自线一二区| 7777色鬼xxxx欧美色夫| 国产男人搡女人免费视频| 波多野结衣黑人系列在线观看| 歪歪视频在线播放无遮挡| 欧美一区二区三区精品国产| 黑人疯狂巨大xxoo| 精品久久久久久久久久香蕉| caopo视频进入离开| ai换脸杨幂被c在线观看| 免费看www| 婷婷中文| 女人爽到喷水的视频免费看| 亚洲日韩精品欧美一区二区|