Official Futaba 6EX, 7C and TM-7 Service Advisory

[Julez]

Hi!

I just got my T6 back from robbe Germany. According to the invoice (0.00€ ), the "software was changed". The board is the same (I marked it with a little scratch), and they marked it with a little blob of black paint at one corner.

Both my ZGUID and my normal RXes do not react without binding, so at least it is safe to say that it does not have the ZGUID any more.

It did not get an "I" sticker, but there is a green, round sticker at the backside now, of which I do not remember if it was there from the beginning or not.

And, all of a sudden, the weather got better, too, after 2 months of rain

Cheers,

Julez

[sweetpea]

Interesting news from Futaba on the TM-7.......

http://2.4gigahertz.com/modules/modu...vers-tech.html


Of course, give the public an electronic device and watch how fast they can screw with it to make it do something it shouldn't or do something unexpected

Note: this was supposedly from Oct but I had not heard of the issue before.

[NormS]

	Quote: Originally Posted by sweetpea
	Interesting news from Futaba on the TM-7....... http://2.4gigahertz.com/modules/modu...vers-tech.html Of course, give the public an electronic device and watch how fast they can screw with it to make it do something it shouldn't or do something unexpected Note: this was supposedly from Oct but I had not heard of the issue before.

Have any of you guys noticed that there seems to be two different FASST versions? In addition to the tech note, check out the transmitter-receiver cross reference on Futaba’s FASST site: http://2.4gigahertz.com/modules/modules-receivers.html

Remember that the 6EX2.4 shipped first with the R606FS receiver, followed by the TM-7 and the R607FS, followed by the 7C2.4 and the TM-14 module (in the 12FG); we’re still waiting for the TM-8. Note that the 7C2.4 and the TM-14 are both compatible with the old R606FS plus all of the newer receivers, but that the TM-7 and TM-8 will only work with the newer receives and not compatible with the R606FS.

Its pretty clear that there are two FASST versions but Futaba’s never said anything about this, unlike Spektrum which openly talks about DSM and DSM2. You have to wonder if there’s something wrong with the 6-channel receiver or the original FASST protocol, or at the very least, what they fixed or improved in the newer ones. Why they decided to not make the TM-7 and TM-8 backwards compatible with the R606FS is another good question.

[rcflyer]

NormS, is the TM-14 using the older or later FASST version?

[XJet]

Just an observation... we held a 3-day turbine meeting here over the weekend (at least 20+ turbine models/fliers in attendance).

Last year at this event there were several FAAST sets (6EX)being used. This year I didn't see a single one. In fact, the *only* 2.4GHz systems anywhere to be seen were Spektrum/JR. There was even a Spektrumized Futaba 14MZ being flown.

[NormS]

	Quote: Originally Posted by rcflyer
	NormS, is the TM-14 using the older or later FASST version?

Well, based on the chart the TM-14 is compatible with all of the receivers so I would have to say that its using the newer version.
If you read the tech notice mentioned by sweetpea at http://2.4gigahertz.com/modules/modules-receivers-tech.html it implies that the “fix” was in the area of re-linking the transmitter and receiver after a loss of sync. I guess the R606FS must have had a flaw or a less robust method of re-linking, which was fixed in the newer receivers. The 6EX/2.4, 7C/2.4 and TM-14 module must be able to deal with the R606FS but the TM-7 and TM-8 can apparently use only the newer method with the newer receivers. Its pretty obvious that in this respect the TM-7 and TM-8 are less functional then the integrated transmitters and the TM-14. They were probably designed first, before the problem with the R606FS was found. I don’t know why futaba doesn’t fix them or make updated versions.

As I recall, the TM-7 shipped right after the 6EX/2.4, but the 6EX/2.4 is compatible with all of the receivers and the TM-7 is not; the entire thing is a little strange. I’m hoping that part of the delay on the TM-8 is to address this issue, but the chart still shows the TM-8 working like the TM-7, i.e. not compatible with the R606FS. I would like to find out what the issue with the R606FS is and if it represents a risk or a problem with the FASST protocol even if you’ve got a TM-14 or an integrated transmitter. Because of these issues and unknowns I’m now thinking of waiting until April and buying the new 10C/2.4 instead of the TM-8 for my 9C super.

[Julez]

	Quote:
	it implies that the “fix” was in the area of re-linking the transmitter and receiver after a loss of sync. I guess the R606FS must have had a flaw or a less robust method of re-linking, which was fixed in the newer receivers.

I do not believe that this is true.
If it was, what would this flaw be, and why have we not heard of anybody who was concerned?
When I range tested my 606s in urban environment, and when I came to the range limit with a couple of buildings in between, the RX lost link and regained the link multiple times within a second. If it is able to regain a link multiple times a second, that is good enough for me. Even if the RX was totally out of sync for some reason, all it would have to do ist to listen on one channel for a signal with its ID. Given the FHSS nature of FASST, it would have to wait max. 0.288sec for this signal.

So far, we only know that there is a difference from what the TM7/8 and what the other systems transmit. To say that the signal from one system is "better", or that a specific RX is "better" or another had a "flaw", is pure speculation, as there is no evidence to support this point of view.

The relinking is only a problem, according to Futaba, when two incompatible parts of the system are forced to work with each other. Don't do that, and you won't have a problem.

[NormS]

	Quote: Originally Posted by Julez
	I do not believe that this is true. If it was, what would this flaw be, and why have we not heard of anybody who was concerned? When I range tested my 606s in urban environment, and when I came to the range limit with a couple of buildings in between, the RX lost link and regained the link multiple times within a second. If it is able to regain a link multiple times a second, that is good enough for me. Even if the RX was totally out of sync for some reason, all it would have to do ist to listen on one channel for a signal with its ID. Given the FHSS nature of FASST, it would have to wait max. 0.288sec for this signal. So far, we only know that there is a difference from what the TM7/8 and what the other systems transmit. To say that the signal from one system is "better", or that a specific RX is "better" or another had a "flaw", is pure speculation, as there is no evidence to support this point of view. The relinking is only a problem, according to Futaba, when two incompatible parts of the system are forced to work with each other. Don't do that, and you won't have a problem.

Of course I’m speculating. Given the absolute lack of any real information from Futaba, what else can we do? But speculation is not always wrong, and in this case, was not baseless. Look at what we have heard from Futaba:
1) This is a direct quote from the tech note on the FASST web page (http://2.4gigahertz.com/modules/modules-receivers-tech.html):
“Interference or loss of battery power could cause loss of signal and the two cannot "re-link" automatically. “

2) Futaba has stated that the R606FS has been discontinued. Here’s a quote of the notice on their web page (http://2.4gigahertz.com/faq/faq-6ex-2_4ghz-q925.html):

“The R606FS was discontinued and is being replaced with the R607FS. As the R606FS was not compatible with the TM-7 and TM-8 modules, it was felt that it was a better move to go with the R607FS which is compatible with all Futaba 2.4GHz modules and transmitters. When used with the 2.4GHz FASST 6EX transmitter the R606FS receiver has proven to be a very reliable system and should give you years of dependable service.”

Based on the above, I think its very clear that Futaba’s receivers utilize two ways of re-linking; the R606FS uses one and all of the newer receivers use another. Since the R606FS was the first receiver shipped and has been discontinued, I think its pretty clear that the newer receivers have been improved, at least as far as their ability to re-link after a loss of signal, which strikes me as a pretty important function. Since the TM-14 and all of the newer integrated systems can operate with both re-linking methods they have to be considered better, in some sense, then the TM-7 and TM-8 which only work with the new receivers.

I’ve always wondered why the TM-7 and TM-8 are different from all of their other systems. One possible answer (speculation warning, Julez) is that the TM-14 and the integrated transmitters all utilize some form of a partly software-based transmission scheme, whereas the TM-7/8 are obviously pure hardware-based transmitters and are thus less flexible.

Actually, Futaba is to be congratulated on recognizing an issue like this and addressing it in their newer systems. They’ve also apparently changed the servo update order in the new R617FS from that used on the R607FS (http://www.rcgroups.com/forums/showthread.php?t=772341&page=3). These are all good things. I own two Futaba transmitters and I fully intend to get a FASST system (or module) at some point in the future. My only real complaint is that they’re keeping us in the dark and making our decisions harder. For example, would an integrated or TM-14 based transmitter be a better choice then an upgrade module for my 9C super?

[Julez]

Hi!

	Quote:
	Since the R606FS was the first receiver shipped and has been discontinued, I think its pretty clear that the newer receivers have been improved, at least as far as their ability to re-link after a loss of signal, which strikes me as a pretty important function.

I still don't quite see, how you come to conclude that there is a flaw in the 606's ability to relink.

The paragraph from Futaba, that you quote, only describes problems with the relinking, when using the 606 with incompatible modules.

Nothing is said about a flaw with the 606 when used with a compatible module or TX.

AFAIK, the relinking information was only issued by Futaba after a user at RCG foud out a way, to link the 606 to a TM7, which was not supposed to be possible the first place.
He had to link it to a T6, then switch the T6 off, while leaving the RX on, then switching a TM7-equipped TX on, and press the bind button, or something alike.
As described, a complicated series of steps. Normally, the 606 was not supposed to be linkable to a TM7 in the first place. Thus, it cannot be expected to have the ability to relink to this module.

Concluding now, that the 606 has a general flaw in relinking, is even more than just far- fetched, IMHO.

It is like trying to put diesel in a gas car. It won't work well. Concluding now, that diesel is an inferior fuel, is a logic fallacy.

Cheers,

Julez

[Four Stroker]

I agree with the kid here.

All the Futaba compatibility chart says is that there are three FASST airborne protocols: 1) T6EX 2) TM-7 and TM-8 in 7 channel mode and 3) TM-8 in 8 channel mode and TM-14 (FASST MULT). The 607 and 617 receivers are apparently backward compatible to the T6EX FASST protocol. We can assume that the TM-14 in 7 channel mode is the T6EX mode since it works with the 606,607,617.

The FASST MULT mode is probably the real FASST. It has 2048 resolution and full fail-safes and will probably be here for a while.

[rcflyer]

Why can't Futaba implement FASST MULT in all their modules?

[NormS]

	Quote: Originally Posted by Julez
	Hi! I still don't quite see, how you come to conclude that there is a flaw in the 606's ability to relink. . . . . Julez

I’ll give this one last shot and then give it up.

The 606 doesn’t work with the TM-7 although the TM-7 works with all the newer receivers. The difference appears to be (at least) in the way the receivers link/re-link with the transmitters.

The 606 was the first FASST receiver Futaba shipped. Futaba could certainly have designed all of their subsequent receivers to link/re-link the same way that the 606 does, but they decided not to and changed the procedure in the 607, 617, 608 and 6014.

Futaba has discontinued the 606. I don’t know exactly when they started selling it or when they officially discontinued it, but this has got to be one of the shortest product lifecycles in their history. Does anyone know the relevant dates?

Given the above, how can you possibly say that there wasn’t some kind of issue with the 606? Futaba obviously felt that there was, since they changed the link/re-link procedure in all of their newer receivers.

Now to be totally fair, there’s another way of looking at this: the link/re-link issue might actually have been caused by the TM-7 module and not the 606. In this scenario, the newer receivers would have been designed to work with either the 6EX or TM-7, and the 7C and TM-14 could actually be working in 606 mode. This could explain the delay in shipping the TM-8 (allowing Futaba to redesign it?), BUT if this was the case, why did Futaba discontinue the 606?
Thanks a lot.
NormS