[NSRCA-discussion] curious

[Bob Richards]

>>>I was trying to make the point that the Futaba FASST modules used in a Futaba radio do not increase the latency for any particular transmitter. <<<
 
Ok, I agree with that.
 
>>>Also, that within the Futaba line the concept of module based versus "native", or built in does not mean much. At least that is what I have been told by the tech folks in Champaign. The 12FG and 12Z with a module both have the same overall latency for instance.<<<
 
I think that would be true for the module based 12Z, 14MZ, and 10C, but those modules have a direct FASST interface and don't have to go through a PPM interface. However, my 8UAPS with the TM-8 FASST I suspect would NOT be as fast as my 10C for that reason. (I may be wrong, but I would be surprised if I were). The radio will have its own latency converting the stick positions to a PPM pulse train. Then, the module will have to receive the pulse train and decode it, then convert it to the FASST protocol. So, you would have the latency already associated with the PPM system (probably 20 to 25ms minimum) and add to that the latency of the FASST (looking at the latency data posted, I would suspect a minimum of 10ms).
 
>>>And I have been told the same thing that the FASST module using the PPM stream in the older transmitters is faster than when those transmitters were using PCM mode. <<<
 
I absolutely agree. I've always heard that the PCM method was slow. The previously posted link shows that to be true.
 
My point was that the TM-7 and TM-8 modules would likely not be as fast as a native 2.4g system.

Bob R.


--- On Mon, 3/22/10, Bill's Email <wemodels at cox.net> wrote:


From: Bill's Email <wemodels at cox.net>
Subject: Re: [NSRCA-discussion] curious
To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
Date: Monday, March 22, 2010, 1:06 AM


I was trying to make the point that the Futaba FASST modules used in a Futaba radio do not increase the latency for any particular transmitter. Also, that within the Futaba line the concept of module based versus "native", or built in does not mean much. At least that is what I have been told by the tech folks in Champaign. The 12FG and 12Z with a module both have the same overall latency for instance.

And I have been told the same thing that the FASST module using the PPM stream in the older transmitters is faster than when those transmitters were using PCM mode.  

Bob Richards wrote: 






--- On Sun, 3/21/10, Bill's Email <wemodels at cox.net> wrote:
If you are using a Futaba FASST module and receives there is absolutely no difference between module based systems and built-in non-module. If you are using another after market module then you may very well be seeing an effect of latency. All other non-Futaba modules will not be as fast as the Futaba module in a Futaba radio.
 
Actually, there are two different type of FASST modules.
 
1) The TM-7 and TM-8 modules fit the older radios (9C included) and must use the PPM pulse train that the older 72MHz modules used.  As such, the transmitter MUST be in PPM transmission mode, so the latency can't be any better than a PPM system. (Which is actually faster than the 72MHz PCM systems from what I understand).
 
2) The 10 and 14 channel modules (10C, 12Z and 14MZ systems). These have a different means of communicating with the modules in native FASST mode, and should be no different than the non-module native 2.4g systems. The latency should be faster than the PPM pulse train used above. 
 
The link previously posted to the latency testing did not show any TM-7 or TM-8 information. I believe these are the only FASST modules that will work in the 9C under question. However, my experience with both in my 8UAPS has been positive.

Bob R.

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