Sekotech ST-300 SPIDER, Руководство по эксплуатации, Страница: 29 / 68

OPERATING MANUAL
27
While in the automatic mode, the probing signal magnitude cannot be changed; it will be used as
set previously in the manual mode.
When the automatic mode is entered, the selection of wire pair remains the same as in the manual
mode; testing results for other pairs are not shown. To move the table cursor, use the
keys.
2.7.2.1 Cable Settings
For cable settings, press “FUNC”. The procedure of setting the cable type and number of connected
wires is identical to the one described in 2.5.1.1. To exit cable settings to the main screen of the
“NONLINEAR JUNCTION DETECTOR” mode, press “ESC” or “FUNC”.
2.7.2.2 Automatic Scanning
To start automatic testing of all the possible wire combinations, press “F4” (“Scan All”). When the
cycle is complete, the “LEVELS” column will be filled with graphic data.
If the voltage in a pair exceeds 3V in absolute value, the corresponding entry in “LEVELS” column will
read, “ >3V ” , and the pair in question will not be tested. If the table cursor is positioned at this line, the
sign will appear in place of the selected pair number (2, Fig.35).
In this event, to proceed with testing, disconnect the cable from the power source (de-energize the
tested circuit).
For the detection of series connections, the line must be short-circuited. For short-circuit testing of
multiwire cables equipped with an RJ45 socket, the Short Circuiter (23, Fig.1) supplied with ST300 is to
be used.
To exit from the automatic mode of NLJD control to the manual mode, press “MODE” or “ESC”. Upon
exit, the highlighted pair number will be retained as current.
2.8 “REFLECTОMETER” MODE
The “REFLECTОMETER” mode of ST300 serves for testing double- and multiple-wire cable with the
purpose of detecting unsolicited electric (galvanic) connections and defects (e.g., twisted connections).
The search method is based on transmitting a sinusoidal signal, that is reflected from a defect or anomaly
and returns with a delay, its phase different from the initial signal. The procedure is repeated at multiple
frequencies, resulting in a spectrum with alternating peaks, showing the distance to a defect in the tested
cable. ST300 can determine said distance with a +/–0.5m precision.
The numbers in Fig. 35 represent:
1 – current mode
2 – wire pair connected
3 – wire pairs column
4 – graphics showing relative response levels at
the second (red) and third (blue) harmonic
frequencies of the probing signal (similarly to
5-6, Fig.34)
5 – table cursor
6 – current assignment of F4 hotkey
Fig.35