IBM System/36 Maintenance Information Manual page 99

1.
25 m
+
35 m
=
60 m
2. 60 m x 2
=
120 m
3. 30 m
+
120 m
=
150 m
4. 200 m
+
150 m
=
350 m
To calculate the distance to the failure:
1. Determine the time in divisions between the start of the
+
B-Gate squarewave and the reflection caused
by the failure.
For example, sample oscilloscope signal
II
("712 Sample Oscilloscope Signals" on page 7-10) shows 6.4
divisions to the reflection caused by the open.
2. Multiply the number of divisions times the length per division for the B-sweep setting shown in the
following distance tables.
Sample oscilloscope signal
II
has a B-sweep setting of 2.0 microseconds. Therefore, the distance to the
failure would be 1267 meters for a twinaxial cable (6.4 x 198) and 1420 meters for an IBM Cabling
System (6.4 x 222).
Distribution Panel
(back view)
DODO
DODO
Wiring Closet
Work Area
200
m 25m
~/
r-----L..,
ii
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System
Legend:
Cable
I I
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Work
Station 1
Data Signal Path
m
=
meters
35 m
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Work
Station 2
Work
Station 3
R36B121-1
Section 7. Local Work Station Procedures
7-9