HE4000 Encoding System
Using the Front Panel
Front Panel Menu
Summary
Command
Function
Options/Response Format
HE4000>Output>
Modulator>
Modulator menu may be
available based on configuration
of unit. This is an optional
feature.
Enable
Displays the present enable
status
Note: The modulator may be set
Enabled, but may automatically
disabled due to a fault condition
of a rate mismatch.
● On – modulator is enabled
● Off – Modulator is disabled
(default)
Output
Enables or disabled the output
from the modulator
● On – modulator is enabled
● Off – Modulator is disabled
(default)
Source
Option to used the modulator as a
stand alone modulator,
independent of the encoder
operation.
● Internal Source (HE4000) (default)
● ASI Input – Feed an external transport stream into
the ASI input for modulation.
Modulation Type
Sets the modulation scheme
● DVB-QPSK
● 8PSK
● 16QAM
Frequency
Sets the modulator carrier
frequency
● 70000000 (default)
52.0 to 88.0 Mhz, 104 to 176 Mhz, 950 to 2050
Mhz.
Symbol Rate
Sets the current transmission
symbol rate
SymRate
Sets the current transmission symbol rate
1.0 to 20.0 Msps
2.0 default: 5.500187 Msps
Data Rate
Sets the data rate for the output
transport stream or the
modulator data rate
If modulator is disabled: 1 to 80 Mbps default:
8.448 Mbps
If modulator is enabled: 1 to 80 Mbps
Code Rate
Sets the rate for forward error
correction (FEC) of the
modulated signal
● 5/6 (default) - 7/8, 1 /2, 3/ 4, 5/6 For QPSK
Power
Sets the Transmit Power
Range is from -2500 to 0
Rolloff
Sets the baseband filter rolloff
factor of the internal modulator.
This parameter must match the
demodulator filter rolloff
● 0.35 (default) normally used for DVB
compliant demodulators
● 0.20
● 0.25
Spectrum
Used to instruct the modulator to
invert, or not invert, the
modulated IF output spectrum.
Inverting the IF output spectrum
eliminates the spectral inversion
in the RF chain caused by
selecting lower side-band images
of an upconverted carrier
● Normal – modulated IF output is not inverted
(default)
● Inverted – modulator inverts the IF output
spectrum
Carrier
Sets the modulation output into
pure carrier mode
● Normal (default)
● Pure Carrier (CW)
Framing
Sets framing mode
● No framing (default)
● DVB 188 Byte Framing
● DVB 204 Byte Framing
3-32
01-0951-404 Rev B