DTX频点测量扫描技术详解
The standards clearly specify what has to be measured and how.
For category 5e and 6, the following must bemeasured: - Wire map
- Length
- Propagation Delay
- Delay Skew
- Insertion Loss (Attenuation)
- NEXT
- PS NEXT
- Return Loss
- ELFEXT
- PS ELFEXT
- DC Loop Resistance*
- ACR*
- PS ACR*
*Not required for TIA/EIA Standards. However,the DTX provides this data for category 5e and 6 Autotests.
Frequency Range - Category 5e measurements are made from 1 MHz to 100 MHz.
- Category 6 measurements are made from 1 MHz to 250 MHz.
- Augmented Category 6 measurements (Draft) are made from 1 MHzto 500 MHz.
- 10GBASE-T measurements (Draft) made from 1 MHz to 500MHz.
Frequency Resolution 
Any DTX owner can verify the information provided in the table above. To do this, run an autotest and view the NEXT plot. Pressing the 
key on the DTX will move the cursor marker on the trace across one point. An example is shown below.
This screen shot was taken from a DTX-1800 CableAnalyzer set to thedraft TIA Augmented Category 6 standard.
Below is a CSV output file from a Category 6 Autotest. Open it inExcel to view the measurements. You should see:-
You can also do this yourself by downloading LinkWare, opening thesample.flw file, viewing the plot and saving it as a CSVfile.
Owners of the DTX-1800 CableAnalyzer have the ability to measure to800 MHz and 900 MHz for Insertion Loss. The frequency resolutionremains at 1 MHz after 500 MHz. An example is shown below. Just goto SETUP > Instrument Settings> Store Plot Data and selectedExtended.
