DTX2CU exercises

Introduction

The best way to learn to is do.

These test results are real results taken from the field.

• Open the file Exercises01to16LinkWare.flw in LinkWare
• Double click one of the result records; another windows will open with detailed test data
• Select Pair Data near the top and HDTDR or HDTDX Analyzer near the bottom of the window

 

Solution

Exercise 01 - cable too long

Notice that the length has exceeded 90m but not failed.

Accept? No.

Why? Insertion Loss failed. Even when the length limit can be exceeded by 10%, cables lengthes exceeding the design length are likely to fail the insertion loss test.

HDTDR/HDTDX: You could look at HDTDR to make sure there is nothing unusual.

Corrective Action: try and remove some slack from the cable run. 

 

Exercise 02 - cable too long

With ISO/IEC11801, length is not a required field test parameter.

Notice that Length is marked with an "i".

Accept? No.

Why? Insertion Loss failed. Even when there is no field test limit for length like in ISO/IEC11801, cables lengthes exceeding the design length are likely to fail the insertion loss test.

HDTDR/HDTDX: You could look at HDTDR to make sure there is nothing unusual.

Corrective Action: try and remove some slack from the cable run. 

 

Exercise 03 - improper cable handling

The result for Return Loss in marginal. Cabling standards deem a marginal PASS* as a PASS. However, the customer or the cabling vendor offering the warranty may not.

Accept? Depends on the contract.

Why? Return Loss is marginal

HDTDR/HDTDX: With HDTDR, in almost all cases, you need to zoom in on the vertical axis so that in the right corner of the screen you see 1X  32X. HDTDR shows the cable to be bad in the last part of the link; consistent with a cable handling issue.

Corrective action: This cable will have to be replaced.

 

Exercise 04 -