VIERLING VIT-A1, Руководство по эксплуатации

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VIERLING
VIT-A1 - 70299.202 - 1.3 – 20050513 27
Switch is positioned
"On / ADSL Test" Switch is positioned
”Off / Line Test"
External electrical
supply is
connected to the
DC socket Battery maintenance
charge Battery quick-charge
(but only if switch is
already in this position
before connecting to
the DC socket!)
No external
electrical supply
connected to the
DC socket Electrical supply
provided over
batteries No electrical
consumption
3.2 Switch On / ADSL Test ↔ Off / Line Test
The flip-switch is used to turn the electrical power supply on and off.
This electrical supply is either routed internally over the batteries or
externally over the DC socket. At the same time, switching also takes
place between testing for a successful ADSL connection set-up (switch
position "ADSL Test") and testing for the presence of a remote current
supply (switch position "Line Test").
Switch Position Off / Line Test
The "Line Test" switch position detects on the customer terminal
connection line being tested whether remote current supply is available
for an analog or ISDN connection. Test results are indicated by the
corresponding "Line Test" LED indicator located on top of the housing.
If test results are positive, then confirmation exists that both wires (a
and b) have been correctly connected during switching. Thus,
accidental "single leg" switching faults are prevented that would possibly
cause ADSL modems to synchronize nevertheless although very
favorable conditions exist otherwise (for example, by minimal line
attenuation).
However, power supply tests should not be executed behind the splitter
of the user-side in the direction of the customer modem since direct
voltage is no longer available at this line location. Thus, it would be