PC-IP Software
User’s Manual
30
Modulation - The type of modulation expected may be setup by
selecting from NTSC, 64 QAM, 256 QAM, PAL-B, PAL-B/G,
PAL-D, PAL-I, PAL-N, QPSK, QPR, DVB-64, DVB-256,
Annex C64 and Annex C256.
Symbol Rate - The symbol rate for the signal being tested is set
automatically for both 64 and 256 QAM (5.056941 MHz for 64
QAM and 5.360537 MHz for 256 QAM). The user may enter
other data to change the default rate to any other data rate. The
symbol rate must be within approximately 0.1% of the actual
rate used for the Install Profiler to demodulate the digital signals
to make MER and BER measurements.
Bandwidth - This is the setting for the allocated bandwidth for
the channel. The bandwidth is defaulted to 6 MHz for Annex B
and C modulation types and to 7 or 8 MHz for Annex A
modulation types depending on the channel’s frequency and
plan. The user may change the default setting.
Video/Audio 1 - This is the setting for the frequency offset of the
primary audio carrier. The offset is defaulted to 4.5 MHz for
Annex B and C modulation types and to 5.5 or 6 MHz for Annex
A modulation types depending on the channel’s frequency and
plan. The user may change the default setting.
Video/Audio 2 - This is the setting for the frequency offset of the
second (NICAM) audio carrier. The offset is defaulted depending
on the channel plan. The user may change the default setting. An
offset of 0 indicates that a second audio carrier is not used.
Analog Pilots - Analog pilots are set to the low and high pilot
typically used to control the automatic gain and slope of the
amplifier or the lowest and highest analog channel. These
channels are used to calculate the tilt of the analog channels in
the automated tests. To select a channel, click on the box and
select the desired channel from the pull down window. Only
active analog channels are displayed in the pull down window.
If these are not set, the Tilt and Peak-to-Valley measurements
should be disabled in the analog SMART tests on the LIMITS
screen.
