Marginal Pass/Fail Band - DTX CableAnalyzer

If the worst case margin falls within the field testers accuracy, it is marked with an asterisk (*).  This is a requirement of ANSI/TIA-1152 and IEC 61935-1.

NEXT Margin Markes as Asterisk

Let's find out which pair had a NEXT margin of 1.9 dB:

NEXT Margin with 1.9 db

To better undestand this, let's draw a graph and put the limit line in as red. Then add the region representing the marginal band, shown in yellow. If the worst case margin should fall into this band, it is marked with an asterisk (*). It is important to understand that the width of the band changes with frequency.

NEXT Accuracy Band for a Category 6A Permanent Link

Let's put our result above for Pair 3,6-4,5 on this graph:

NEXT Accuracy Bandwith TestResult for a Category 6A Permanent Link

It just falls within the accuracy band, hence the * on our test result.

Since accuracy is dependent upon frequency, it is possible to have two results with the same margin, but only one of them reported as marginal.

If you are looking for the specific frequency points of the marginal band in the form of tables and graphs, please click here: (13.4MB)