FlyingGiants Exclusive! Introducing The Futaba 12FG, Modules & More!

[toprudder]

	Quote: Originally Posted by klhoard
	According to BAX over on RCU, the 2.4 modules give the radio the same speed and resolution as PPM mode in 72 Mhz.

I'm sure that is true for the modules in the old radios (must be in PPM mode to talk to the modules) but I'm not sure that is the case with the 12 and 14 channel radios.

Bob R.

[klhoard]

	Quote: Originally Posted by toprudder
	I'm sure that is true for the modules in the old radios (must be in PPM mode to talk to the modules) but I'm not sure that is the case with the 12 and 14 channel radios. Bob R.

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Here ya go. . .
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http://www.rcuniverse.com/forum/m_63...tm.htm#6331305
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You can ask Bax himself. . .
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[toprudder]

	Quote: Originally Posted by klhoard
	You can ask Bax himself. . . .

Done! Will see what answer I get.

[Julez]

Hi!

Module systems, that capture the PPM frames and digitalize it, are always slower than a 100% PPM system. You will never see a transmission latency of less than 0.1 ms (see attachment, done with Futaba R 118 reciever) in a system that has to sample pulses, as the modules have to.
Due to the fixed transmission frame rate of the modules (8ms), the module's and the transmitter's framerate are not synchronized.
As they are asynchronous, logic dictates that the latency can be at least as high as the module's framelength.

quote from Bax

Futaba has the 6EX and the 7C on FASST coding that do not use modules.

At least the 6EX uses PPM sampling on it's internal RF module like the external modules will.
(see animated attachment that compares the 6EX pulsetrain to the pulsetrain of a Futaba transmitter which is compatible to external modules.)
So, we will not see a difference concerning transmission latency when comparing the "non- module" 6EX to external module systems.

Cheers,

Julez

[Julez]

Hi guys,

I may have interesting news.

Fasst does not transmit all channels with each burst.
I mixed a switch on channel 2 and 5 at my transmitter. When I flip the switch, the pulswidth change of both channels occurs synchronous in the PPM pulsetrain of my TX, as verified with the scope.

If Fasst transmitted all channels' information with each burst, the pulsewidth change would also occur synchronous in each reciever frame.
It does not.
In some cases, channel 5 is updated earlier than channel 2.

My explanation is the following: After each sampling of the pulsetrain, the gained information is stored in the Fasst module. This information is used when the module transmits the 1st burst for the first channels, and when it transmits the 2nd burst for the last channels.
However, these bursts with a length of 2ms occur every 8ms.
Thus it is possible, that the pulsetrain information is updated between the 1st and the 2nd burst. In this case, the last channels get "fresher" information than the first ones.
Exactly this event one can see in the scope screenshot.
In the 2nd frame, channel 5 is updated, while channel 2 still has its old value. Finally, in the 3rd frame, channel 2 is also updated.

One can discuss the advantages and disadvantages of this technique.
The advantage is, that the average latency of all channels is reduced.
The disadvantage is, that there can be a latency difference of up to 16ms between individual channels in one and the same frame.

Perhaps some heli guy can elaborate on "swashplate dance"?

However, only transmitting half of the channels in each burst is surprisingly few information. Perhaps this contributes to the robustness of the transmission?

Cheers,

Julez

[ben_beyer]

I got my Futaba 12 FG today and it's awesome. You can go from a ratcheting throttle stick to non-ratcheting throttle stick just by turning a few screws on the back. And it has a lot of features, I LOVE IT!

[klhoard]

	Quote: Originally Posted by ben_beyer
	I got my Futaba 12 FG today and it's awesome. You can go from a ratcheting throttle stick to non-ratcheting throttle stick just by turning a few screws on the back. And it has a lot of features, I LOVE IT!

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Is this the 2.4G system?
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[smokedat]

I just went into the darkside i was a JR user but i just got a 12FG let me tell you its a whole lotta radio its like magic will upgrade to the Futaba 2.4 module when its available so i have the capability to swap around, i got tired of waiting for the 2.4 version plus the fact i dont really trust this new tech.

[dubd]

Any of you 12FG users notice how quickly the battery goes from fully charged (8.4v) to 7.4v? Seems like if I use the menus for programming about an hour the battery needs to be recharged again.

[ben_beyer]

	Quote: Originally Posted by klhoard
	. . Is this the 2.4G system? . .

No, I'm holding off on 2.4 for gassers for a while until they improve the systems.

dubd,

I have noticed the same problem, but now that I've discharged it 3 times, it took 1633 maH on the charger last night so we'll see how long that lasts. The previous times it only took around 300 maH. Maybe it's something with NiMH chemistry.

[klhoard]

	Quote: Originally Posted by ben_beyer
	. . .. . Maybe it's something with NiMH chemistry.

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Yes, you need to cycle NiMH's a few times to get them to "form". Slow charge at first a couple times and their capacity will open right up. .
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[ben_beyer]

With the exception of my LiPo packs for parkflyers, that's all I do is slow charge lol. All of my batteries whether they be my Fromeco packs, NiMH RX batteries, or TX batts get .2 amps from my Accu Cycle Elite. It may take a while to charge them, but they don't even get warm. And I put my TX on the Accu Cycle Elite again last night and it took 1633 maH. I've never seen this with the NiMH batts, but I know about it now.