Scientific Atlanta Continuum DVP eXtra Dense QAM Array 24, Configuration Manual

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Chapter 3 Configuring the XDQA24 System
Output Level
The output level of a RF output depends on the Channel Mode parameter. When
the Channel Mode parameter is set to Dual Channel, the output level can be
adjusted between 45 and 55 dBmV. When this parameter is set to Single Lower
Channel or Single Upper Channel mode the output level can be adjusted between 50
and 60 dBmV. This parameter is adjustable in steps of 0.5 dBmV and the default
value is 50 dBmV.
Note: If you set the output level to a value outside this range, a message box is
displayed.
Symbol Rate
The symbol rate of an ITU-C version XDQA24 system varies between 5.0 and 5.5
Mbaud and the symbol rate of an ITU-A version between 5.0 and 7.0 Mbaud. The
XDQA24 system allows setting the symbol rate in steps of 0.001 Mbaud.
For an ITU-B version the symbol rate is fixed to 5.056941 and for 64 QAM and
5.360537 for 256 QAM.
Note: If the symbol rate is set to a value outside this range, a message box is
displayed.
Spectrum Inversion
The spectral inversion can be enabled to invert the asymmetric QAM spectrum if
the set-top box cannot invert the spectrum itself. The spectral inversion is default
disabled.
RF Output
The XDQA24 system allows switching off each RF output channel of a Quad
Channel QAM card. If the RF output is switched off, then an alarm is generated.
The RF output is default enabled.
Lower and Upper Channel Signal Format
The RF output can be set to different modes: viz.:
-
Normal: the channel is on.
-
Diag. Mute (diagnostic Mute): the channel is muted without affecting the
adjacent channel. This mode is useful for test purposes.
-
Continuous Wave: the modulation of the channel is switched off.
Channel Mode:
The channel mode can be set to the following values:
-
Single Lower Channel: the upper channel will be disabled at the output
-
Single Upper Channel: the lower channel will be disabled at the output
-
Dual Channel: both the lower and upper channel will be enabled at the output
Note: After changing the Channel Mode parameter, a small interrupt will occur
on any active channel of the corresponding output.
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