[linux-dvb] [PATCH] Fix the unc for the frontends tda10021 and stv0297

e9hack e9hack at googlemail.com
Mon May 12 08:47:54 CEST 2008


P. van Gaans schrieb:
> Not necessarily. Here some femon output from my Technotrend T-1500:
> 
> status SCVYL | signal  54% | snr  99% | ber 188 | unc 0 | FE_HAS_LOCK
> status SCVYL | signal  54% | snr  99% | ber 230 | unc 0 | FE_HAS_LOCK
> status SCVYL | signal  54% | snr  99% | ber 240 | unc 0 | FE_HAS_LOCK
> status SCVYL | signal  54% | snr  99% | ber 234 | unc 0 | FE_HAS_LOCK
> status SCVYL | signal  54% | snr  99% | ber 228 | unc 21 | FE_HAS_LOCK
> status SCVYL | signal  54% | snr  99% | ber 248 | unc 0 | FE_HAS_LOCK
> status SCVYL | signal  54% | snr  99% | ber 280 | unc 0 | FE_HAS_LOCK
> status SCVYL | signal  54% | snr  99% | ber 234 | unc 0 | FE_HAS_LOCK
...
> I see the standalones hickup as well. So a very short 
> error will cause unc, but no higher BER.

You may not see a higher BER, because the corrupted signal doesn't hit the BER measuring 
period. Femon asks every 1 second for new values. The UNC counting interval is this 1 
second, but the BER measuring interval is shorter (50..200ms). For a stv0297, it is 150ms 
for QAM256 modulation and 200ms for QAM64. The real measuring interval for the BER is a 
fixed number of bits.

-Hartmut



More information about the linux-dvb mailing list