Promax PROLINK-4C Manual De Instrucciones página 166

Finally it is shown a status line with information about the detected signal. The
possible messages that can appear and its meaning are showing the following list. The
messages are exposed from less to more fulfilment of the MPEG-2 standard:
No signal received
No signal has been detected.
Timing recovered
Only it is possible to recuperate the symbol time.
AFC in lock
The system automatic frequency control can identify and lock a digital
transmission (TDT) but its parameters can not be obtained. It can be due to a
transitory situation previous to the TPS identification (Transmission Parameter
Signalling) or well to a TDT transmission with an insufficient C/N ratio.
TPS in lock
The TPS (Transmission Parameter Signalling) are decoded. The TPS are
carriers (17 in the 2k system and 68 in the 8k system) modulated in DBPSK,
containing information related to the transmission, modulation and codification:
Modulation type (QPSK, 16-QAM, 64-QAM), Hierarchy, Guard Interval, Viterbi
Code Rate, Transmission mode (2k or 8k) and Number of the received frame.
MPEG-2
Correct detection of a MPEG-2 signal.
In case of detecting a DVB signal, message MPEG-2 DVB-T will appear and
the DVB Channels Identifier function will be automatically activated. (See section
'4.9.2 DVB Channels Identifier: DCI function').
DVB-T channels tuning may require an adjusting process. It is recommended to follow
next procedure:
1.- From the spectrum analyser mode, tune the channel at its central
frequency.
2.- Switch to TV mode, BER measuring mode.
3.- If in the lower line of the screen does not appear MPEG-2 message (and
consequently BER is unacceptable), by turning the rotary selector deviate
the tuning frequency until MPEG-2 message appears. Finally tune channel
again to minimize the frequency deviation which optimizes the BER and
therefore minimize the BER.
If it is not possible to detect any MPEG-2 channel, make sure that digital signal
parameters are correctly defined and if signal level is too low, check that the 30 dB
attenuator is not activated (Attenuator 0 dB).
Page 46
USER'S MANUAL. PROLINK-4C
IMPORTANT REMARK
02/2003