REFLECTOMETER
51
After finishing the measurements, the response level (Fig.51, item 11) and the distance to the
heterogeneity, the response from which has the highest level (Fig.51, item 10) are displayed in
the cell.
After that, the tabular cursor moves to the next row and the measurements are repeated for
another pair of wires. After the measurement on all combinations of wires, the scan ends.
The table will be filled with measurement results.
According to the results of the measurement cycle on all pairs, the maximum measured value
of the response level is taken as 100%. The remaining values are scaled in percent relative to the
maximum.
In case of need carrying out repeated measurement on specific pair need to be set the tabular
cursor on the corresponding line and press "F3" ("Test").
If there is a voltage of more than ± 3 V on the connected pair of wires, this pair cannot be
tested using the REF. This blocking voltage is indicated by the "OVER" icon on the indicator of the
connected pair of wires (Fig.51, item 2).
To test such a cable, it is necessary to de-energize it.
It is possible that the external interference to the cable under test (including de-energized) will
be very large. In this case, the work of the REF will be blocked and "Noise" will be displayed in
the table.
To continue testing, it is necessary to find out the cause of the cues, try to eliminate them and
then continue the measurement.
5.4.4. MANUAL MODE
When testing a cable in the AUTOMATED mode the operator obtains information sufficient for
preliminary estimate of existence or lack of rough implementations in the tested cable and
determination of "suspicious" pair of wires.
For obtaining more detailed information on all responses received when testing such pair of
wires it is necessary to use the MANUAL mode.
For turning on the MANUAL mode from the REF main menu:
set the tabular cursor on the row corresponding to "suspicious" pair of wires;
press "F1" or "ENTER".
The MANUAL menu has two tables. The operator can make two cycles of measurements, and
then compare their results. The gray color of the table fields is a sign that the table is active
(available for measurements).
Use of two tables is advisable:
when comparing results of testing of two pairs one multi-wire cables,
when comparing results of testing of two different two-wires cables,
when testing one pair from different ends of the cable.
MANUAL mode menu is shown in Fig.53.
