Operation Manual

DTX Series CableAnalyzer
Technical Reference Handbook
6-4
Table 6-1. Diagnosing Twisted Pair Test Failures (cont.)
Characteristic impedance exceeds the limit or an anomaly is detected
• Bad connection
• Cable compression (tight cable ties, pinches, kinks, etc.)
• Mismatch of cable types
• Water in cable jacket
• Excessive loading at coaxial cable tap
• Incorrect terminator value (coaxial cable)
Length gives a FAIL result
• Cable is too long (may need to remove coiled service loops)
• NVP is set incorrectly
Length exceeds the limit, but the length test did not fail
If the length of the shortest pair does not exceed the limit by 10 %, then the length test passes even if other pairs exceed the
limit. This is the 10 % rule for length, as given in the ANSI/TIA standard. See the Fluke Networks Knowledge base for details.
Propagation delay or delay skew gives FAIL result
• Cable is too long (may need to remove coiled service loops)
• Cable uses different insulation materials on different pairs
Insertion loss gives FAIL, FAIL*, or PASS* result
• Cabling is too long
• Poor quality patch cord
• Bad connection
• Wrong cable type in installation
• Wrong test standard selected