Cisco DNCS System Release 2.8.1 3.8.1 4.3.1 User Guide

In general, the system sets up the QPSK modulator advanced parameters automatically, and you should not
change them. However, if you need to change any advanced parameters after you have set up the basic
parameters, keep in mind the following guidelines and contact Cisco Services if you need further assistance.

Important: If you change any of the default parameters, you must stay within the signal capacity of your plant
design. Otherwise, the DHCTs might not be able to communicate with the DBDS. In addition, you must reboot the
QPSK modulator and wait for all corresponding DHCTs to sign on again before any changes take effect.

Configuration File Name

Do not change this parameter without first consulting Cisco Services.

Service Channel Frequency

Enter a value from 8 to 26.5 MHz based on your plant design.

This parameter establishes the frequency that the DHCTs use to broadcast to
the demodulators on this hub.

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.

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.