Cisco DNCS System Release 2.8.1 3.8.1 4.3.1 User Guide

A QPSK modulator processes data going downstream from the DNCS to the DHCTs, as well as data going
upstream from the DHCTs to the DNCS.

For example, a QPSK modulator takes programming data for a PPV event from the DNCS, processes it onto an
RF signal, and then sends it to the DHCTs. When a subscriber chooses to buy that event by using their remote
control to send a signal to the DHCT, the DHCT passes that signal back to the DNCS, first through a QPSK
demodulator, and then through a QPSK modulator.

For more information on QPSK modulators, refer to DAVIC QPSK Demodulator Model D9492 Installation and
Operation Guide (part number 545617).

Note: We offer a software product that enables the DNCS to also transport DOCSIS-compliant CMTS data to
DHCTs. For more information about this software product, 

.









