Black Box TS1002A, TS1003A, TS1000A-R5 manual 101

CHAPTER 6: Diagnostics

the NEXT at the connection point, which is typically located at the end of the test cable at 2 meters (7 ft). The measurement unit for the horizontal graph can be displayed in meters (m) or feet (ft). (See Chapter 3, Setup for further information about units.)

Initially, the cursor is located at the point with the worst NEXT.

The NEXT at the cursor position relative to the S-Band, the corresponding pair combination, and the distance to the cursor position are displayed above the graph.

The example shows a Time Domain NEXT that exceeds the S-Bands. The worst NEXT is displayed at 7.0 ft, the connection location. The conclusion is that the connection caused the failure.

Press ESC to exit the TDNXT screen.

6.3.1USING TDNXT TO DIAGNOSE A LINK

The S-Band limit lines provide an easy method to pinpoint faults located at the connection or the cable. S-Bands allow you to determine if the connections in a link meet the desired performance level. They are designed to match the standard category of the selected Autotest.

A graph containing peaks that are located outside the S-bands at the connection distance indicates that the connection and not the installed cable is the most likely reason for failure.

If NEXT failed but the TDNXT graph displays peaks within the S-Bands at the connection distance, the fault is caused by the cable portion of the link.

If failures occur at both ends of the link, use or to diagnose each end. Failures at both ends of the link can interact.

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