Re: TBS 6921 release date
Posted: Sun Jan 23, 2011 11:06 pm
BluetoothBG Wrote:- about issue 02 - TBS6921 is not responding (no lock on existing/known transponders) ONLY after blind scan with 22 kHz ON and needs "full" restart. From my observations this is the only case when the card is not responding. If I do only a low-band scan everything is OK.
it's good to know that actually issue 01 and 02 are connected and probably due to some mix up with the 22 kHz tone control between the BSTool and the driver. i will look at it as soon as i have some spare time from my on-going projects.
BluetoothBG Wrote:Feature requests:
- is it possible scan to be some kind of automatic - you don't have to select polarity and hi/low band? It'll be good to have this options but leave them in "manual" mode and by default to be "automatic".
noted and it will be done. however, in a little different way than you suggested, because no all LNB have hi-band and/or understand 22 kHz tone. so, polarity will be automatic (with way to select manual mode) and include check-box "do subsequent scan with 22 kHz on" to indicate after scan with 22 kHz off another one to be run with 22 kHz on for LNBs for which 22 kHz tone make difference.
BluetoothBG Wrote:- input and output frequencies to be in MHz and in "transponder range" (I mean 10.7 to 12.75 GHz, not 950 MHz to 2150 MHz)
"transponder range" actually depends on the LNB type and it's LOF frequencies - so, technically the range is always some sub-range of 950 MHz to 2150 MHz. maybe, why to make it more user-friendly is to add drop-down menu with predefined more common types of LNBs for user to select his/her LNB type and if not input the specifications of the LNB manually, which will allow to calculate the "transponder range".
BluetoothBG Wrote:- provide some kind of filters (maybe for Symbol rate, e.g. if I want to scan only for transponders with SR < 10000 MSym/s and if this will make the scan faster - if there is no way to provide "input" filters for the NXP chip, these filters are not needed I think)
What I can show you as an example is a screenshot of SkyStar v2.3 hardware blind scan tool (source: http://www.r00t.cz/Misc/Blindscan)
This is exactly what I'll be glad to see as an TBS BSTool, if all of this options are available from the hardware design/NXP chip.
here you misunderstand and there is no advantage in doing such thing - let me elaborate and explain. during blind-scan always the whole or some sub-range of 950 MHz to 2150 MHz is scanned - it's a lot like spectral analyzer - first all active frequencies in the interval are found and then their modulation parameters are determined. so, SkyStar v2.3 in the old DVB-S era probably was the only hardware for computer that can do blind-scan. however, it's very old and its chips are very old and if you look at VP310 and TSA5059 datasheets (PDF files are available online) you will understand that this is not "filter", but actually hardware limitation - they can do blind-scan for only predefined symbol rate interval. so, if you want to scan frequency interval X for all possible SRs then you need to do several blind-scans - as many as the number of the SR ranges and thus it's not performance-wise, but exactly the contrary it's slower. the latest third generation of DVB-S2 chips by NXP that is found on TBS 5921/6921/8921 scan for all possible SRs with a single pass, which is better from performance point of view. if my explanation is not clear, let me give example: old SkyStar v2.3 has 16 SR intervals and if you what to scan one frequency range for particular SR interval then the time for that is Y seconds (the time is always the same no matter of the SR interval, because as i mentioned first step of a blind-scan is like spectral analysis - find all active frequencies in the scanned frequency range) and that means for 16*Y seconds are needed to blind-scan of all possible SRs, but with newer NXP chips if they do spectral analysis part for Y1 seconds then Y1 seconds gives blind-scan of all possible SRs. so, in very short SkyStar v2.3 needs 16 passes, for what newer NXP chips do in one single pass.