User Manual

61
APPENDIX
Bad cable (Near end short): The error is displayed as follows:
12> 27' SHORT
36> 26' OPEN
45> 25' OPEN
78> 26' OPEN
EXIT DETAILS
12> ------- SHORT
36> 26' OPEN
45> 25' OPEN
78> 26' OPEN
EXIT DETAILS
The SHORT on 12> is most likely at the connector (near end). If the
short is on the FAR END of the cable it would look like this:
Bad cable:
Near End Short
Bad cable:
Far End
Short
OPENs in cable pairs generate errors in both in SKEW tests and
in wire map tests. The following example shows a 200’ cable with
a break in the middle on pair 78. The following is the fi rst screen to
show a problem.
Bad cable:
Open
Note there are two problems shown. The SKEW (difference in DE-
LAY between pairs) is much greater than 50 NS. Another problem
SKEW > 50 NS
LENGTH = 98'
DELAY 148 NS PASS
SKEW 150 NS FAIL
EXIT DETAILS