Promax MO-180 Manual De Usuario página 109

USER'S MANUAL MO-180
MIP LOSS
In SFN or MFN using the option of configuring the modulator from the
Megaframe Initialisation Packet (MIP), this status flag being active indicates that no
MIP has been found in the HP/LP TS's during at least one megaframe.
MIP ERROR
In SFN or MFN using the option of configuring the modulator from the MIP, this
status flag being active indicates that a MIP packet has been found in an HP/LP
megaframe but it has format errors (using the MPEG-2 TS syntax, this amounts to
transport_error_indicator
transport_priority being 0 or transport_scrambling_control not being "00" or
adapatation_field_control not being "01" or synchronization_id not being "0x00" or
section_length < 19 or section_length > 182 or pointer > 10583 in HP or pointer > 7055
in LP).
1pps ERROR
In SFN this status flag being active signals that the number of 10 MHz clock
periods between two consecutive active edges of the 1pps signal differs from 10
Tx Frequency Offset
In SFN or MFN using the option of configuring the modulator from the MIP, this
is the integer carried in the MIP used to apply a deliberate frequency offset of the
central frequency of the transmitted DVB-T signal relative to the centre frequency of the
RF channel. The valid range goes from —8388608 Hz to 8388607 Hz. Note that this
offset is NOT automatically applied to the modulator output.
Tx Radiated Power
In SFN or MFN using the option of configuring the modulator from the MIP, this
is the positive number carried in the MIP which can be used to configure the transmitter
Effective Radiated Power (ERP). The valid range is 0 dBm to 6553.5 dBm in steps of
0.1 dBm.
HP/LP Net Delay
In SFN, these are the network delays for the HP and LP transport streams.
These delays are expressed in µs with a resolution of 100 ns. Because of the way
there are obtained, these values have to be further corrected by subtracting 2 TS
packet periods from them.
(the error is always strictly less than 1 TS packet period). The network delay is defined
as the delay between the (multiple channel) SFN adapter output(s) and the TS input(s)
to the modulator.
The TS packet period in µs is easily obtained by dividing 1504 by the useful bit rate of the DVB-T/H mode expressed in
4
Mbits/s. Thus, for instance, for 64QAM, rate 2/3 and guard interval 1/4, we have a TS packet period of 1504/19.9058824
= 75.56 µs. Note that in hierarchical modes we have to deal with the HP and LP TS packet periods separately.
04/2008
being 1 or payload_unit_start_indicator
4
The result is an upper bound on the actual network delay
being 0 or
7
.
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