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Old Nov 02, 2012, 05:15 PM
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Originally Posted by Elios000 View Post
would seems in theory the best system would use 2 or 3 channels at the same time and leap frog them
ie one channel hops then the other with them hoping all the time
kind of a hybrid DSMX/FASST system with the hopping of FASST and the multichannel of DSMX
DSMX "hops" just like FASST. (Like as in "the same general fashion", not as in "the same dwell and hop timings")
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Old Nov 02, 2012, 05:33 PM
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DSMX only hops as needed
think dwell and hop but with 3 channels with only one channel hopping at a time
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Old Nov 02, 2012, 05:42 PM
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Originally Posted by Elios000 View Post
DSMX only hops as needed
think dwell and hop but with 3 channels with only one channel hopping at a time
You may care to clarify that .
It sounds like you mean only 3 channels are involved
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Old Nov 02, 2012, 05:54 PM
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Originally Posted by Elios000 View Post
DSMX only hops as needed
think dwell and hop but with 3 channels with only one channel hopping at a time
I am not exactly sure what you mean by that, but...

Think it through... what would be the advantage of that? Is it actually any different from what FASST does?

And... DSMX hops all the time from what I understand. It doesn't do like some systems and stick on one channel until there's an issue with that channel - it actually can't do that because there's no back-channel to tell the transmitter what is happening out at the receiver.
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Old Nov 02, 2012, 06:01 PM
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I am not exactly sure what you mean by that, but...

Think it through... what would be the advantage of that? Is it actually any different from what FASST does?

And... DSMX hops all the time from what I understand. It doesn't do like some systems and stick on one channel until there's an issue with that channel - it actually can't do that because there's no back-channel to tell the transmitter what is happening out at the receiver.
You do know that DSMX has various hopping arrangements which are peculiar to a specific tx.

each DSMX tx has a GUID which is it's own and utilizes 23 channels.
I don't know how many different GUID sequences (tx) are used
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Old Nov 02, 2012, 06:04 PM
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Originally Posted by Elios000 View Post
DSMX only hops as needed
think dwell and hop but with 3 channels with only one channel hopping at a time
No, DSMX hops constantly. You can actually prove this by forcing a Spektrum transmitter into DSMX mode (after binding a receiver in DSM2 mode) and noting how you'll have brief moments of "jittery" control whenever the transmitter happens to hop on to one of the two DSM2 frequencies.
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Last edited by jsipprell; Nov 02, 2012 at 06:16 PM. Reason: got it backwards
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Old Nov 02, 2012, 06:07 PM
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You do know that DSMX has various hopping arrangements which are peculiar to a specific tx.
I don't remember how many patterns are used - someone must have that number --
Yes, but they should be relatively equal in terms of time spent on each frequency, from one TX to the other. I am still not clear on what Spek means by "Smart" hopping or "adaptive" or whatever they call it... but I'm pretty sure it's not adapting to anything happening at the receiver.

That is - if there's 30 channels, I would expect that ALL transmitters spend 1/30th of their time equally on each of those channels, regardless of differences in the pattern. Like, how many different ways can you write the numbers from 1 to 30 in different order, while only using each number once... 30-factorial? I don't know, but it's a lot.... and they all use each channel one time in the pattern. So, I don't think there should be any difference between one transmitter and the next.
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Old Nov 02, 2012, 06:08 PM
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You do know that DSMX has various hopping arrangements which are peculiar to a specific tx.
I don't remember how many patterns are used - someone must have that number --
I presumed it was pseudo-random based on a seed of the model's (ModelMatch) uuid or something similar, but I have no real data to back that up.
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Old Nov 02, 2012, 06:11 PM
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Yes, but they should be relatively equal in terms of time spent on each frequency, from one TX to the other. I am still not clear on what Spek means by "Smart" hopping or "adaptive" or whatever they call it... but I'm pretty sure it's not adapting to anything happening at the receiver.
I think they mean "adaptive" in the same way Hitec means it; analyze the environment at bind time and avoid congested areas of the band but once everything is up and running the channels in use don't change. (Hitec actually requires you to activate a special "mode" for this).
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Old Nov 02, 2012, 06:13 PM
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You do know that DSMX has various hopping arrangements which are peculiar to a specific tx.

each DSMX tx has a GUID which is it's own and utilizes 23 channels.
I don't know how many different GUID sequences (tx) are used
I looked it up It is probably like the old GM key sequences - there were a bunch of em but not an infinite bunch
eventually the same key would open another car
In this case tho - -there would have to be an "impossible" condition of two identical GUID tx operating at exactly the the same instant in time.
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Old Nov 02, 2012, 06:20 PM
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That is - if there's 30 channels, I would expect that ALL transmitters spend 1/30th of their time equally on each of those channels, regardless of differences in the pattern. Like, how many different ways can you write the numbers from 1 to 30 in different order, while only using each number once... 30-factorial? I don't know, but it's a lot.... and they all use each channel one time in the pattern. So, I don't think there should be any difference between one transmitter and the next.
A random number between 1 and 2.65*10^32 would give you a unique pattern of 30 channels.
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Old Nov 02, 2012, 06:23 PM
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I looked it up It is probably like the old GM key sequences - there were a bunch of em but not an infinite bunch
eventually the same key would open another car
In this case tho - -there would have to be an "impossible" condition of two identical GUID tx operating at exactly the the same instant in time.
guids are typically implemented as a uuid (universally unique identifier); a 128-bit number between 0 and 5.310^36; so the chances of a collision are practically nil even if every person on earth was given a radio.

(They take the format "21CF2350-3AFC-1F69-B5E3-08222C96418D", and if you look around at various technologies you'll likely recognize that format all over the place)
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Old Nov 02, 2012, 06:26 PM
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Ah wuzzunt worried --
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Old Nov 02, 2012, 06:31 PM
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Originally Posted by jsipprell View Post
guids are typically implemented as a uuid (universally unique identifier); a 128-bit number between 0 and 5.310^36; so the chances of a collision are practically nil even if every person on earth was given a radio.

(They take the format "21CF2350-3AFC-1F69-B5E3-08222C96418D", and if you look around at various technologies you'll likely recognize that format all over the place)
GUIDs SUCK! I hate them

A database I work with, for some reason, uses GUIDs as surrogate keys. I basically said "until you change that, I'm not making any performance guarantees"
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Old Nov 02, 2012, 06:37 PM
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GUIDs SUCK! I hate them

A database I work with, for some reason, uses GUIDs as surrogate keys. I basically said "until you change that, I'm not making any performance guarantees"
I have to confess to having used/generated UUIDs on occasion, but not for table indices.

They are particularly useful as a pseudo-random seed, if you generate them from a high entropy (really random) source and save/share them you can reliably reproduce an infinite set of "random" numbers that is always the same sequence.
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