關于CAT7測試——七類網線CLASS F測試的解決方案

七類線纜認證測試標準在TIA的標準數據庫中是直接跳過，取而代之的是八類的通道測試標準，真正認證七類測試的是在ISO標準數據庫中，找到ISO11801 CHANNEL CLASS F或者FA，這就是標準的七類測試標準，測試頻率需要達到500MHZ，我們將通過實際測試，闡述七類測試的要點。關于CAT7測試——七類網線CLASS F測試的解決方案

七類測試之前，會被DTX-1800或者DSX5000系列強制認定自校準，這個過程和標準的設置基準是一樣的操作。

To test to 1 GHz, please look to the DSX-5000 CableAnalyzer which has been approved by Siemon. 

TERA  is Siemon's Category 7 connector used in Class F and FA cabling systems. It's a non RJ-45, shielded connector. Since it is not RJ45 based, you cannot use your DTX-PLA001 with DSP-PM06 or DTX-PLA002 Permanent Link Adapters. Likewise, you cannot use your DTX-CHA001, 001A or 002 Channel Adapters. 

由于七類是針對類似西蒙等標準大廠特殊的接口而設計的適配器，所以使用傳統的RJ45通道適配器或者**鏈路適配器都是不支持的，必須使用TERA或者GG45的特定接口適配器才支持測試七類。關于CAT7測試——七類網線CLASS F測試的解決方案類似下圖：

You need to order the DTX-TERA kit. You will need a DTX-1800 CableAnalyzer. If you have a DTX-1200 CableAnalyzer, it can be upgraded to a DTX-1800 CableAnalyzer by purchasing the DTX-1200 Enhancement Kit, Part Number: DTX-1218E. 

Do NOT order just the DTX-PLA011 TERA Permanent Link Adapters. You will also need at least one DTX-CHA011 TERA Channel Adapter so you can Set Reference with the main and remote units. (Shown below)關于CAT7測試——七類網線CLASS F測試的解決方案

測試標準
You will find the Class F and FA test limits under the ISO folder:

Class FA is rated to 1,000 MHz (1 GHz). However, when you select a Class FA limit in the DTX CableAnalyzer, the test limit will stop at 600 MHz. Why?  To answer this, we'll look to what the standard states. ISO/IEC 11801 Amendment 1 and 2 defers testing requirements to IEC 61935-1. 

In IEC 61935-1 we see the following text:

6.7 Accuracy performance requirements for Level IV field testers over 600 MHz .The Level IV requirements shall apply to measurements of class FA cabling up to 600 MHz and pass/fail evaluation criteria shall apply. Measurement data over 600 MHz shall be provided for information only. Detailed requirements over 600 MHz are for further study.

Accuracy becomes a real issue above 600 MHz for field testing. At 1,000 MHz, the Insertion Loss accuracy is going to be at least +/- 6 dB. 關于CAT7測試——七類網線CLASS F測試的解決方案
 
At the heart of the problem, is that in the field, the main and remote unit can be up to 100 m (328 ft) apart from each other. The end-to-end measurements (Insertion Loss and FEXT) are going to be compromised due impedance mismatches. In the laboratory, both ends are terminated into a laboratory network analyzer. So the meaasurement is going to be more accurate because you can calibrate for impedance mismatches. But that is impossible if both ends are not close together, as in the field. There is no feasible solution other than making the mismatches as small as possible, which is what the DTX CableAnalyzer does. As a result, at the last IEC 61935-1 meeting, no field test equipment manufacturer came forward with an accuracy proposal above 600 MHz. The test equipment manufacturers present were Fluke Networks, Ideal Industries and Agilent. Despite this, there continues to be claims of Level IVe accuracy to support Class FA. There is no such thing, not even in any draft standard. 
In the current code for the DTX CableAnalyzer, Class FA has been added to the tester. The limit will stop at 600 MHz as per IEC 61935-1. However, the measurement will continue to 900 MHz for Insertion Loss, ACR-F/PS ACR-F and 800 MHz for all other parameters. 
Siemon accepts testing to 600 MHz for their warranty approval. 關于CAT7測試——七類網線CLASS F測試的解決方案
If you purchase the kit (recommended), part number DTX-TERA, it will come with (2) DTX-PLA011 and (2) DTX-CHA011.

關于CAT7測試——七類網線CLASS F測試的解決方案