RunRyder - TX/RX eCCPM Latency Test Results

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Radio - Servo - Gyro - Gov - Batt > TX/RX eCCPM Latency Test Results

w.pasman
Elite Veteran
Location: Netherlands

Great job!

You might consider adding the values I measured for the FF8S. They are in my reports.

08-03-2005 Over year old.

HOMEPAGE

JKos
Elite Veteran
Location: Town of California in the state of Maryland

w.pasman,
> You might consider adding the values I measured for the FF8S

Very true. I'll do that tomorrow (later today, really

). I also have an 8U available to test. Isn't an 8U the same as an FF8? Yes, I know yours was a "Super", though, right?

I really need to get a 10X to test as well. I thought I had one available, but it has been loaned to a new heli pilot.

- John

08-03-2005 Over year old.

geeo
Senior Heliman
Location: Edinburgh, Scotland

Nice work

Any chance of testing a hitec eclipse 7 yet??

08-03-2005 Over year old.

JKos
Elite Veteran
Location: Town of California in the state of Maryland

> Any chance of testing a hitec eclipse 7 yet??

The hold up on testing the Eclipse 7 is getting my hands on a QPCM receiver. I just can't find anyone local with one. The LHS says no one asks for them and thus they don't stock them or order radio sets with them.

If anyone has one they can spare for a week or so (counting mailing time), I could do the tests and get it back to you.

Thanks,
John

08-03-2005 Over year old.

w.pasman
Elite Veteran
Location: Netherlands

JKos

Quote
Isn't an 8U the same as an FF8?

I think "FF" is a term (short for "field force") used by Robbe, which resells (or used to resell) futaba stuff under it's own brand name.

There seem to be slight differences. Check my web page
http://graphics.tudelft.nl/~wouter/...aff6/types.html

From that, it seems be that Robbe asks for minor software changes, but those seem merely related to the software configuration settings.

I would keep the FF8 and FF8s (the "normal" and the "super") versions separate. Futaba must have modified the software to add the "super" functionality, which might also involve performance changes.

08-04-2005 Over year old.

HOMEPAGE

w.pasman
Elite Veteran
Location: Netherlands

Quote
Yes, I know yours was a "Super", though, right?

Yes that's right

08-04-2005 Over year old.

HOMEPAGE

JKos
Elite Veteran
Location: Town of California in the state of Maryland

Due to many differences between w.pasman's tests and mine, I will not be putting his numbers in my table. The differences include 36 MHz system vs 72 MHz (this seems to effect the system timing), standard swash mode vs eCCPM mode, and watching a single channel vs watching all three channels used for eCCPM control.

His numbers can be found in his report to which I gave a link earlier in this thread.

- John

08-04-2005 Over year old.

JKos
Elite Veteran
Location: Town of California in the state of Maryland

This just in... Test results for the Hitec Eclipse 7 using both QPCM and FM receivers The table in the first post of this thread has the numbers.

- John

08-22-2005 Over year old.

Blair
Key Veteran
Location: Republic of Canuckistan

Interesting post.

Any new revelations since August?

Blair

12-05-2005 Over year old.

JKos
Elite Veteran
Location: Town of California in the state of Maryland

Nothing new to report. I still need a 10X to test.

- John

Protos -- Logo 14 -- Logo 10

12-07-2005 Over year old.

rroback
Key Veteran
Location: Irvine (UCI), Ca

John, my spektrum dx6 is still yours, I haven't forgot, but I still have not received it yet. Once I get it, i'll send it on to you. Do you want everything, or just tx, and rx?

Rhett... There's no power like E Power!

12-07-2005 Over year old.

JKos
Elite Veteran
Location: Town of California in the state of Maryland

I've added the new Spektrum DX6 to the list. A little on the slow side, but more consistent and well behaved compared to either JR or Futaba PCM. BTW, the eCCPM performance is very good. Full change of all three channels in one frame.

- John

Protos -- Logo 14 -- Logo 10

01-04-2006 Over year old.

JKos
Elite Veteran
Location: Town of California in the state of Maryland

I thought I would add a few graphs to perhaps help get a feeling for how the radios do relative to each other. The first graph shows the minimum and maximum latency for eCCPM use as well as the average.

The second graph shows the average deviation of the four reported latency numbers in the table in the first post of this thread. This number could be described as just how variable is the radio's perceived latency. The human brain is quite good at accounting for constant delays in control systems (i.e., being ahead of the helicopter with stick movements) but not nearly as good when the delay varies widely. Therefore, a radio with larger latency but a smaller deviation of the latency may indeed "feel" better than a radio with lower latency but larger deviation.

- John

Protos -- Logo 14 -- Logo 10

01-05-2006 Over year old.

w.pasman
Elite Veteran
Location: Netherlands

Great job!!! IMHO this comparison would be the first thing to check when looking for a new radio. But apparently most people look for other things, judging from the number of comments on your nice work

I see you also got your hands on an HiTek Eclipse 7, great. And that it does not perform exceptionally well, especially since your test was in FM mode.

Why are there two plots for "futaba 14MZ R50 14DPS", but with different values?

Maybe it's an idea to differentiate more clearly between the digital and analog modes? That would make it easy to quickly find the best digital and best analog system, and see how they compare.

Also maybe you could make the lines a bit thicker than one pixel, and/or generate a higher-resolution plot?

Finally, do you have an idea Futaba would be with PPM modulation? I'm assuming that all futaba points in the plot are PCM.

01-05-2006 Over year old.

HOMEPAGE

JKos
Elite Veteran
Location: Town of California in the state of Maryland

w.pasman,
Thank you for the nice words. Once I got the setup and method down it has been fun doing the measurements.

Quote
I see you also got your hands on an HiTek Eclipse 7, great. And that it does not perform exceptionally well, especially since your test was in FM mode.

I tested the Eclipse 7 in both PCM and FM mode. Both are shown in the table and on the graphs. The ones which say "QPCM" were in PCM mode and the ones that say "FM" were in PPM mode.

Quote
Why are there two plots for "futaba 14MZ R50 14DPS", but with different values?

Ah, yes. I need to make that clearer on the graphs. In the table you'll see that I list the numbers for using both concurrent channels (such as 4,5 and 6) and for using the "old" Futaba channels of 1, 2, and 6. The slower numbers are for the "old" channel case.

The point of showing both cases here as well as in my "eCCPM behavior" thread is to show why people should be using the newer channel assignments and not just stick to the old school channels.

Quote
Maybe it's an idea to differentiate more clearly between the digital and analog modes?

If a specific receiver is listed after the transmitter name (or QPCM in the case of the Eclipse 7), than it was in PCM mode. The ones which say "FM" were in PPM mode.

Quote
Also maybe you could make the lines a bit thicker than one pixel, and/or generate a higher-resolution plot?

I can redo the plots, no problem. They did come out a bit smaller than I wanted. I will also notate the difference between the two 14MZ/R5014DPS cases. [EDIT: New plot uploaded.]

Quote
Finally, do you have an idea Futaba would be with PPM modulation? I'm assuming that all futaba points in the plot are PCM.

Yes, all of the Futaba numbers were in PCM mode. I don't know why I didn't get numbers for PPM mode as well.

I'll say it again... I'll test ANY radio I can get my hands on. If someone wants a specific radio tested, send it my way and I'll get it done and back to you very quickly.

- John

Protos -- Logo 14 -- Logo 10

01-05-2006 Over year old.

Shortman
Key Veteran
Location: Clovis, California

Is the Futaba 7C running the same latency as the 9C?

01-05-2006 Over year old.

JKos
Elite Veteran
Location: Town of California in the state of Maryland

Steven,
Futaba did something very odd with the 7C and 9C Super. They imposed a rate limiter on collective changes. No matter how fast you move the collective stick, the output at the receiver only changes so fast. Given that behaviour, I didn't even try to measure the latency.

Graphs of this behaviour can be seen in this thread: http://www.runryder.com/helicopter/t171302p1/

And, to answer a question that may come to mind... Yes, a human can most definitely move the stick fast enough for this rate limit action to occur. I would love to see someone try a fast, tight tic-toc with a 7C or 9C Super. It takes over 300 ms for the radio to accomplish full collective change!

- John

Protos -- Logo 14 -- Logo 10

01-06-2006 Over year old.

rroback
Key Veteran
Location: Irvine (UCI), Ca

I suppose under most circumstace i'd say the spektrum dx6 was slow, but since it's only for parkflyers, it doesn't seem so bad. the eclipse fm did pretty well, for a quite cheap radio. do you have any interest in graphing a jr 8103?

Rhett... There's no power like E Power!

01-06-2006 Over year old.

Shortman
Key Veteran
Location: Clovis, California

Hmm, well looks like I have my work cut out for me

01-06-2006 Over year old.

RappyTappy
Elite Veteran
Location: Las Vegas, NV

Quote
I would love to see someone try a fast, tight tic-toc with a 7C or 9C Super. It takes over 300 ms for the radio to accomplish full collective change!

Is this limitation only on CCPM?

Chris
Rex 500
Burning them electrons :D

Forever Brothers
Mickey Tylo

01-06-2006 Over year old.

HOMEPAGE

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Radio - Servo - Gyro - Gov - Batt > TX/RX eCCPM Latency Test Results

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