EXFO FTB-635 Wideband Copper and DSL Test Module - Manual (Page 262)

Noise Tests
254 FTB-635
NEXT
NEXT
The NEXT test measures the Near End Crosstalk (NEXT) in dB, between 2
pairs of cables: the calculation is a ratio and a larger value is better. The test
transmits a signal on the T/A - R/B pair, and measures the received
crosstalk on T1/A1 - R1/B1 pair. The test has 2 modes of operation: Spot or
continuous and Spectrum or snapshot.
Hookup Diagram
The NEXT test optionally displays a hookup diagram in a popup window at
the start of each mode, showing you how to connect 2 pairs. The
appearance of this diagram at test startup can be controlled in Application
Settings/General. The hookup diagram uses the following graphic and
textual components:

OK button closes the hookup diagram prompt and starts the test.

Cancel button closes the hookup diagram prompt only; you must tap
Start to run the test.