Cisco Headend System Release 2.7 Installation Guide
Chapter 1 Initial Installation of RNCS Software
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Backup Service Channel Frequency—If you are NOT using a backup service
channel, enter the same value in this field that you entered for the Service
Channel Frequency parameter on the basic parameters tab. Otherwise, enter
a value from 8 to 26.5 MHz based on your plant design.
Important: We recommend that you not use a backup service channel. The
backup service channel is used when the service channel fails. All reverse
channel messaging is sent over the channel on which the DHCT achieves
initial sign-on. If a backup service channel is in use, the DHCT may not be
able to achieve initial sign-on.
channel, enter the same value in this field that you entered for the Service
Channel Frequency parameter on the basic parameters tab. Otherwise, enter
a value from 8 to 26.5 MHz based on your plant design.
Important: We recommend that you not use a backup service channel. The
backup service channel is used when the service channel fails. All reverse
channel messaging is sent over the channel on which the DHCT achieves
initial sign-on. If a backup service channel is in use, the DHCT may not be
able to achieve initial sign-on.
Tuner Input Attenuator—The DHCT calibration setting based on the design
targets of your RF plant and the combining networks. If you need assistance,
contact Cisco Services. The system will not connect to any levels that are in
the fail range.
targets of your RF plant and the combining networks. If you need assistance,
contact Cisco Services. The system will not connect to any levels that are in
the fail range.
8 Click Save. The system saves the advanced parameters for this modulator in the
DNCS database and closes the Set Up QPSK Modulator window. The QPSK List
window updates to include the new QPSK modulator.
window updates to include the new QPSK modulator.
9 Cick File > Close to close the QPSK List window.
10 Add the new QPSK modulator to your network map.
10 Add the new QPSK modulator to your network map.
Add a QPSK Demodulator
A QPSK demodulator performs data error correction, and then passes the data
upstream to the QPSK modulator. The QPSK demodulator also monitors power
levels and slot timing of incoming set-top signals. You can assign up to eight QPSK
demodulators to one QPSK modulator.
upstream to the QPSK modulator. The QPSK demodulator also monitors power
levels and slot timing of incoming set-top signals. You can assign up to eight QPSK
demodulators to one QPSK modulator.
Note: We offer a software product that enables the DNCS to also transport DOCSIS-
compliant CMTS data. For more information about this software product, contact the
representative who handles your account.
compliant CMTS data. For more information about this software product, contact the
representative who handles your account.
Adding a QPSK Demodulator
Important: Be very careful when you add a QPSK demodulator. Incorrectly
configuring demodulators causes large numbers of DHCTs to be classified as non-
responding units. In addition, the network management system will falsely log
errors originating from incorrectly configured QPSK demodulators.
configuring demodulators causes large numbers of DHCTs to be classified as non-
responding units. In addition, the network management system will falsely log
errors originating from incorrectly configured QPSK demodulators.
After you add a QPSK modulator to the RNCS, complete these steps to add all QPSK
demodulators that are connected to that modulator.
1 On the DNCS Administrative Console, click the DNCS tab.
2 Click the Network Element Provisioning tab.
3 Click QPSK/CMTS. The QPSK/CMTS List window opens.
4 Select the modulator to which you need to assign this demodulator.
5 Click File > Demodulators. The QPSK Modem window opens with an
demodulators that are connected to that modulator.
1 On the DNCS Administrative Console, click the DNCS tab.
2 Click the Network Element Provisioning tab.
3 Click QPSK/CMTS. The QPSK/CMTS List window opens.
4 Select the modulator to which you need to assign this demodulator.
5 Click File > Demodulators. The QPSK Modem window opens with an
illustration of the modulator and its eight possible port connections.