User Manual

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power cycle.
- Monitoring the status of the equipment.
- Recording events and alarms.
- Firmware upgrades.
- Digital Precorrection through RS232 port and dedicated PC software interface.
1.4.7 TEST MODES
Two test modes are available, to be used only for laboratory or field test. The test modes are directly accessible
from the user menus and are:
1) PRBS Sequence: the ASI/SMPTE input signals are ignored and a 23-bit PRBS sequence replaces the
input payload of the MPEG-TS packets. This test allows measurements on the modulated signal without
the need of a valid ASI/SMPTE input signal.
2) Single Tone: the normal 8-VSB output spectrum is switched off and replaced by a sinusoidal output useful
for frequency converters alignment.
Note: If test mode 2) is active, the ATSC TRANSMITTER does not generate a valid ATSC 8-VSB signal.
1.4.8 POWER HANDLING
After the ATSC TRANSMITTER is powered on, it starts radiating a valid ATSC 8-VSB signal within a short
time. The maximum initial power-on delay is about 20s as factory default value. Any modification of this initial
power-on delay is to be done with the support of the Elettronika Customer Service.
If a valid MPEG-TS signal is received over one of the ASI/SMPTE inputs, then the equipment will immediately
generate the signal on the RF output. In absence of a valid MPEG-TS signal the equipment can be set to be
muted or not.
Enabling the muting function is possible by the user menus, as explained in the Menu Management section of
the present manual.
All the working parameters of the ATSC TRANSMITTER are stored into a non-volatile memory in the
modulator section, so that there is no need to restore the parameters after a power off/on cycle.
The power handling is characterized by 3 states: MUTE, POWER UP and POWER ON.
z MUTE (POWER LED off, fan off): the internal amplifier is switched off by inhibiting the RF transistors
gate.
z POWER UP (POWER LED blinking, fan on): the internal amplifier is switched on and the output power,
starting from -3dB to the final level, is slowly increased following a linear ramp law.
z POWER ON (POWER LED on, fan on): the internal amplifier is switched on (normal working operation).