Cisco Headend System Release 2.7 User Guide
Chapter 9 Monitor DHCTs with the DHCT Status Reporting Utility
130
4031374 Rev B
midpoint between our recommended transmission level of 25 and 55 dBmV. This
graph represents a healthy system; the vast majority of DHCTs assigned to this
QPSK modulator transmit within our recommended range of 25 to 55 dBmV.
graph represents a healthy system; the vast majority of DHCTs assigned to this
QPSK modulator transmit within our recommended range of 25 to 55 dBmV.
Notice the Current Tuner Input Attenuation Level of 2 in the header of this graph.
This value is set at the Tuner Input Attenuator field, which is located on the
Advanced Parameters tab in the Set Up QPSK Modulator window on the DNCS. A
Current Tuner Input Attenuation Level of 2 corresponds to an attenuation level of -5
to 11 dBmV that currently exists on the network. DHCTs base the strength of their
transmitting signal on this Current Tuner Input Attenuation Level. The higher the
Current Tuner Input Attenuation Level, the stronger the transmitting signal; the
lower the Current Tuner Input Attenuation Level, the weaker the transmitting
signal.
This value is set at the Tuner Input Attenuator field, which is located on the
Advanced Parameters tab in the Set Up QPSK Modulator window on the DNCS. A
Current Tuner Input Attenuation Level of 2 corresponds to an attenuation level of -5
to 11 dBmV that currently exists on the network. DHCTs base the strength of their
transmitting signal on this Current Tuner Input Attenuation Level. The higher the
Current Tuner Input Attenuation Level, the stronger the transmitting signal; the
lower the Current Tuner Input Attenuation Level, the weaker the transmitting
signal.
Transmit Level Analysis
The second part of the DHCT Transmit Level Saturation Report provides a chart
showing the detailed breakdown of the graphical data displayed in Graphical
Distribution of DHCT Transmit Levels (on page 129). This part of the report
contains the following data:
showing the detailed breakdown of the graphical data displayed in Graphical
Distribution of DHCT Transmit Levels (on page 129). This part of the report
contains the following data:
Total number of DHCTs assigned to the modulator and each demodulator that
transmit at each transmit level
Note: In the following example, the QPSKMOD1 modulator is configured with
eight demodulators.
transmit at each transmit level
Note: In the following example, the QPSKMOD1 modulator is configured with
eight demodulators.
The average and the median transmit level for the modulator and each
demodulator
demodulator
The data confirms that the system is healthy. The average and median transmit
levels (marked Avg. and Md respectively in the heading of the chart) for the
modulator and each demodulator are reasonably close to the midpoint (40 dBmV) of
our recommended range of 25 to 55 dBmV.
levels (marked Avg. and Md respectively in the heading of the chart) for the
modulator and each demodulator are reasonably close to the midpoint (40 dBmV) of
our recommended range of 25 to 55 dBmV.