That seems unlikely.
J-20 5th Gen Fighter Thread V
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Brumby
Major
When you mentioned huitong I checked up on the site and it was actually where I saw it mentioned that the J10A was using ARINC429 data bus.
As to HSDB it may be MIL-STD-1773 which is clocked at 100Mbits/sec and is the fiber optics version of MIL-STD-1553 that I referenced as on the PAKFA.
Yes, I'm aware of both points.
Regarding "optic HSDB", I'm not sure if use of the acronym is meant to relate to the specific MIL-STD in question or if it's being used merely as a generic term, but I'd put my money on the latter, in the same way that J-20's IRST was called an "EOTS" in some quarters (despite obviously not being the same product on F-35), or how J-20's EO passive detection apertures has been called "EODAS" (despite obviously not being the same product which is fit on the F-35).
Brumby
Major
I would disagree. In terms of data buses used in both military and commercial planes there seem to be some universal standard across the board unlike sensors.
I think if HSDB really was referring to the specific MIL-STD, I believe it would have been described as such consistently. After all, a MIL-STD for a data bus is more than only the data rate, but encompasses a whole host of other standards as well, so I would be surprised if they would have desired a particular Chinese aircraft to have a specific data base with all parameters the same as MIL-STD-1173.
And the way in which it is written on huitong's site -- "J-20 also incorporates an advanced optic HSDB system," -- makes it sound like it is referring to a generic type of data bus (one which is "advanced," "optic," and "high speed") rather than a specific MIL-STD.
Still, if you really wish to ask, Huitong is here on the forum sometimes, or you can go onto his site's message board to see what he really meant.
edit: and better yet, where he got that piece of information from... because sometimes I think he makes some claims which are a result of his own deduction. Of course that's why we rarely take anyone's word as gospel during PLA watching.
Brumby
Major
There are frankly two different issues in play. The primary one was your view that HSDB is a generic description that could mean anything just like IRST. Whilst that may be true as a general argument I am of the view that data buses do follow certain protocols and standard in application unlike IRST and therefore has a much more narrower path in what may be adopted. Beyond that it is speculation what that may be but as I pointed out there is a MIL-STD-1553 and the corresponding fibre optic version MIL-STD 1773. This is also a natural step or two up from ARINC429 that China was using on the J10. If you wish to insist that it is some other unknown standard then that is a general speculation as compared to what I have laid out. MIL-STD-1553 is after all a widely adopted standard. The Russians also adopted it for MIG-35 and is rumored for the PAKFA although I would suspect is probably MIL-STD-1773.
The secondary point is if huitong just mentions it as HSDB then either the person doesn't know the specifics or is not technically inclined to be more specific.
Regarding your first point, I do understand that HSDB exists as a specific acronym for a specific product, in this case generally referred to the MIL-STD-1773.
However, I'm saying that in this case it is very likely that the use of the acronym is referring to the general words itself rather than the specific product, in the same way that some (including Huitong) incorrectly used the acronyms (which happen to be product names) EOTS or EODAS to refer to J-20's EO IRST and EO passive detection apertures.
So, I think that to suggest that HSDB in this case refers specifically to MIL-STD-1773 is as speculative (if not more so) as to suggest that it is merely referring to a general "high speed data bus," because it is a much more very precise claim rather than my position which is a more general claim that doesn't necessarily exclude your suggestion, because we don't have enough evidence to definitively exclude anything yet.
Regarding your second point, yes he likely doesn't know the specifics, after all he collates various credible rumours from the Chinese BBS to provide a summary of his perception of the development situation. I would be very surprised if the Chinese BBS had managed to get any such detailed information to say that J-20 would use such a specific data bus... that is another reason why I'm skeptical that the HSDB in this case refers to MIL-STD-1773, because having that kind of detailed information about such a vital system in the aircraft at this stage of its development (for a PLA project, remember) is virtually unheard of.
Still, I'll ask directly to see what's up.
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Brumby
Major
I did not insist that it is. I am simply arguing that it might be based on data buses architecture standard available and the reasons that I gave. You offered a different view as more probable as something other than MIL-STD-1773 but without any accompanying reasoning other than plausibility. In short, we have both stated our views and should move on.
No, if you're going to dismiss the premises for my position I need to clarify what I perceive as yours and what I believe mine is.
From what I can see, the reasons you gave for suggesting that J-20 maybe using MIL-STD-1773 is because of two things:
1: your belief the original statement about J-20 using "HSDB" meant that the HSDB was referring to MIL-STD-1773 specifically
2: and that MIL-STD-1773 is a natural progression of ARINC429
I OTOH hold two positions,
1: we do not know what J-20 is using apart from the possibility that is is an "advanced optic HSDB", because I believe that the acronym HSDB in this case is not referring to any specific MIL-STD or product, but rather used as a general term (which would correspond with Huitong's past misuse of other specific product names like EOTS and EODAS as general terms).
2: and so following from that, there is no particular reason to believe that J-20's use of a MIL-STD-1773 equivalent would be a natural progression from ARINC429, because for all we know J-10B might use a MIL-STD-1773 equivalent and J-20 could use a more advanced optic HSDB, or maybe their avionics industry has not grown very well and maybe J-20 is using a databus which is inferior to MIL-STD-1773.
So I'm not necessarily saying that J-20's data bus may necessarily be something other than MIL-STD-1773, but that we do not have sufficient reason to believe it could be that vs anything else. It all basically comes down to the interpretation of what "advanced optic HSDB" means.
Brumby
Major
This position is fine (in bold) but that wasn't what you said initially that caused my disagreement. I interpreted your statement below that one outcome is more probable than the other.
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