Length; Delay/Skew; Insertion Loss (Attenuation) - Fluke DSX-600 CableAnalyzer Troubleshooting Handbook

Length

Test Result
Length exceeds limits
Length reported is
shorter than known
length
One or more pairs
significantly shorter
Note: Standard practices dictate that the cabling length be defined by the length of the shortest pair. NVP
varies per pair, meaning each pair could be reported with a different length. These two conditions can result in
a cable with three of four pairs over the length limit, yet the link result is a PASS (e.g. a channel with 101, 99,
103, 102 meters for the four pairs). A PASS in this case is the correct interpretation.

Delay/Skew

Test Result
Exceeds limits

Insertion Loss (Attenuation)

Test Result
Exceeds limits
Possible Cause of Result
• Cable is too long – check for coiled service loops and
remove in this case
• NVP (nominal Velocity of Propogation) is set incorrectly
• Intermediate break in the cable
• NVP is set incorrectly
• Damage to cable
• Bad connection
Possible Cause of Result
• Cable is too long – Propagation Delay
• Cable uses different insulation materials on different
pairs – Delay Skew
Possible Cause of Result
• Excessive length
• Non-twisted or poor quality patch cables
• High impedance connections – Use time domain
techniques to troubleshoot
• Inappropriate cable category – e.g. Cat 3 in a Cat 5e
applications
• Incorrect autotest selected for cabling under test
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