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01-02/2013 —
TELE-audiovision International —
全球发行量最大的数字电视杂志
4. Channels received by the tuner can be descrambled with one of
the two plugged in CAMs. It’s interesting to note that each channel
can be individually paired with one of the two CAMs.
5. The ‘Mux’ tab takes care of re-multiplexer configuration, which
could not be easier: on the left side you select a source channel
and by clicking on the arrow button pointing to the right it is added
to the target stream. Selecting a channel on the right side and
using the arrow button pointing to the left, the channel is removed
from the target stream.
6. The NDS3975 is a professional device, which is why it comes
with a fully implemented BISS decoder inside. Simply enter the
current BISS key, select the BISS version and you’re done.
dress of the NDS3975 (IP
192.168.1.210 in our case)
and confirming it all param-
eters of the receiver can be
accessed, read and changed
as required. This is way fast-
er and much more efficient
than making all adjustments
directly on the box.
Each device is shown in
the tree structure with a vir-
tual LED in front of its name.
This LED lights up in green
whenever a connection be-
tween software and receiver
is established, and if no con-
nection is possible this is in-
dicated with a red light. We
believe this is an extremely
user-friendly solution and
for large installations, in
particular, you can identify
potential problems at a sin-
gle glance.
On the left side of the
MUX tab all received chan-
nels are listed according to
input, while the software
lists channels that should
be packaged into the out-
put stream on the right side.
This way it does not take
rocket science to set up a
new Mux.
In fact, you don’t even
have to consult a manual.
Once the final settings have
been transferred to the
NDS3975 our meter with
ASI input detected the in-
coming transport stream.
What’s more, all channels
of the stream could be re-
ceived nice and clear.
Next, we turned to the
Dectek DTU-215 Gold. First,
we set up the MuxXpert
software – which is avail-
able as an option – to make
sure the IP stream from the
NDS3975 is handed over di-
rectly to the DTU-215, which
in turn would take care of
modulating the stream into
a DVB-C signal.
At this point you should
take care of the input band-
width, which must not ex-
ceed the maximum band-
width for the selected
modulation. At the begin-
ning we simply could not re-
sist the temptation of add-
ing too many channels to a
single transponder, but after
we had reduced that number
to six everything was alright
and worked flawlessly.
The frequency that was
created with MuxXpert
(447MHz, 64QAM, SR 6875)
could then be received and
processed with any stand-
ard DVB-C receiver. Even all
additional features and ser-
vices such as teletext were
available without a glitch.
The conclusion we drew
from building our own lit-
tle head-end station was
that this was not only an
interesting and worthwhile
undertaking, but can also
easily provide residential
accommodation, hotels or
hospitals with complete TV
bouquets via DVB-C/T or
IPTV.
As always, we put the in-
tegrated tuner itself to a
thorough test as well. The
results show that it is able
to lock a signal even if the
antenna is on the small
side and delivers a rather
sketchy input signal.
What’s more, we also tried
to provoke errors feeding
the IP input with a faulty
transport stream – but to no
avail! Turning the transport
stream via ASI and IP off
and on again did not bother
the NDS3975 either, it per-
formed brilliantly whenever
a stream was fed to one of
its inputs.
All that happens when the
ASI cable is disconnected,
or the feeding receiver is
switched off, for example,
is that the status LED ceas-
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