30
ST300 SPIDER
Use the and keys to change the active table.
The inactive table will retain its last measurement cycle data, and a new measurement cycle will start
automatically in the active table.
Data of the last measurement cycle will be discarded from the active table, if
– the automatic mode is started, or
– the reciprocal velocity factor value is changed, or
– a different cable type is set.
Any data in the inactive table will be kept.
Upon exit from the “REFLECTОMETER” mode to the Start Menu of ST300 (2.2), or to the “SWITCH”
mode (2.4), any data obtained the “REFLECTОMETER” mode will be discarded.
2.8.2 Automatic Reflectometer Mode
The automatic reflection meter mode is an optimized way of testing a multiple-wire cable. The operator
can keep track of testing results on all two-wire combinations simultaneously. For each pair of wires, the
table will be showing data on:
– magnitude of the signal reflected from an irregularity;
– levels of mutual inductance/capacitance between the wires of each pair.
This should be enough for the user to make a quick assessment of the results as they appear during
the automatic test. Once the testing has ended, the data obtained can be analyzed automatically. As
a result, one learns about the ‘paired’ wires in a twisted pair cable, approximate length of the cable,
and number of anomalies, with the indication of the wire pairs where they have been discovered and
approximate distances to those anomalies.
The automatic mode is especially useful while testing a multiple-core cable consisting of twisted pairs.
To activate the automatic mode, press “MODE” while in the main screen of “REFLECTОMETER” (2.8.1).
A table will appear on the screen.
If the automatic mode is activated while no wires are connected to the device’s input (connected pair
field reads “0-0”), no measurements will be taken. Upon first activation of the automatic mode, the table
will be empty (Fig.39).
Depending on the type of cable and number of wires in it, the pair legend may change:
the pair is being tested and is a single twisted pair (as opposed to two wires from different
twisted pairs); the cable type is set to ‘twisted-pair’;
the pair is being tested, and the two wires are from different twisted pairs;
the pair is not being tested (if at least one wire so numbered has been excluded as a result
of setting the cable type).
Fig.39
In Fig.39 the automatic mode table is shown, with the cable
type set to four twisted pairs. This kind of cable is typically
used in LANs.
In the figure, all the eight wires of the cable are connected,
and the pairs 1-2, 3-6, 4-5, and 7-8 are paired together
(highlighted blue). The color scheme of such cable is shown
in Appendix #1.
Controls in the automatic mode:
“F2” – set the velocity factor (reciprocal value)
“F3” – activate automatic analysis of the test data
“F4” – activate automatic testing
“MODE” and “ESC” – exit to main screen
“FUNC” – cable settings
– table navigation
“ENTER” – one-time measurement on the pair (highlighted by table cursor).