Chapter 7
Cable Testing Fundamentals
7-11
DC Resistance Errors
All four pairs of a network link should have approximately the same resistance.
Pair resistance that exceeds the limit is indicated as a failure. The maximum limits
in the default tables are based on the maximum length limit of the link or cable
segment.
Troubleshooting DC Resistance Problems
Problem: Excessive Resistance
Probable Causes Mismatched cable types.
Poor punch block connection.
Poor RJ-45 termination connections.
Wire pair has a tap (never done).
Cable damage.
Shorted cable.
Other Tests Affected Test Possible Result
Wire Map May fail.
Attenuation May fail.
NEXT May have false readings.
Capacitance May fail.
Problem: One wire pair has a very high DC loop resistance, others
are normal.
Probable Causes Poor connection points.
Cable damage.
Connector blades not fully piercing wire insulation.
Worn Connector
Other Tests Affected Test Possible Result
Wire Map May fail.
Attenuation May fail.
NEXT May have false readings.
Capacitance May fail.
To Next Page
Loading...
Need help?
General