2.4 Latency Charts are here [Archive]

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DebianDog

02-04-2008, 04:03 PM

JKos (http://www.helifreak.com/private.php?do=newpm&u=3001) is the owner of these charts and info so please PM him with questions, as I do not know. I just wanted this all together and in one thread ;)

http://www.helifreak.com/attachment.php?attachmentid=37624&stc=1&d=1202158882
http://www.helifreak.com/attachment.php?attachmentid=37625&stc=1&d=1202158882
http://www.helifreak.com/attachment.php?attachmentid=37626&stc=1&d=1202158882
http://www.helifreak.com/attachment.php?attachmentid=37627&stc=1&d=1202158882

PCM, DSM, DSM2, FASST, XPS in eCCPM Mode
|
Transmitter |Receiver|MLF|MLL|MaxLF|MaxLL|Avg
---------------+--------+---+---+-----+-----+-----
ATX Stylus |92186Z |13 | 16| 27 | 30 | 21.5
Futaba 12Z |R5014DPS|14 | 14| 31.5| 31.5| 22.75 (1)
Futaba 12Z Md A|R5114DPS|11 | 11| 29.5| 29.5| 20.3 (1)
Futaba 12Z Md B|R5114DPS|15 | 15| 37.6| 37.6| 26.1 (1)
Futaba 12Z/TM14|R6014FS |19 | 19| 57.8| 57.8| 38.4
Futaba 14MZ |R5014DPS|14 | 14| 31.5| 31.5| 22.75 (1)
Futaba 14MZ |R5014DPS|14 | 24| 31.5| 41.5| 27.75 (2)
Futaba 14MZ |PCM1024 |29 | 93| 42 |106 | 67.5 (3)
Futaba 14MZ |DM8/AR9 |20 | 23| 74 | 76 | 47 (4)
Futaba 9C |R149DP |44 |110| 57 |123 | 83.5
Futaba 9ZWC2 |R149DP |29 | 93| 41.9|105.9| 67.5
Futaba T6EX |R606FS | 8 | 15| 54 | 60 | 34.25 (5)
Futaba T7C 2.4 |R617FS |11 | 13| 39 | 41 | 26.4
Hitec Eclipse7 |QPCM |41 | 43| 62 | 64 | 52.5
JR 8103 |649S |27 | 59| 47 | 59 | 48
JR 9303 |649S |15 | 47| 36 | 47 | 36.3
JR 9303 |770S |15 | 47| 36 | 47 | 36.3
JR 9303/Spektru|AR9000 |40 | 45| 63.8| 68.3| 54.4
JR 9303/XPS |XPS 8-ch|33 | 52| 74 | 81 | 60
JR X9303 |AR7000 |24 | 26| 45.5| 49.5| 36.2
JR X9303 |R921 |24 | 26| 45.5| 49.5| 36.7
JR 10X |649S |34 | 66| 54 | 66 | 55
Spektrum DX6 |AR6000 |59 | 63| 80.6| 88.6| 72.8
Spektrum DX6i |AR7000 |23 | 25| 47.6| 49.6| 35.74
Spektrum DX7 |AR7000 |14 | 16| 36 | 40 | 27.5
Spektrum DX7 |AR6100 |14 | 16| 36 | 40 | 27.5
Spektrum DX7 |AR6000 |31 | 35| 53 | 61 | 45
|
|
PPM and eCCPM
|
Transmitter |Receiver|MLF|MLL|MaxLF|MaxLL|Avg
--------------+--------+---+---+-----+-----+-----
ATX Stylus |FM |13 | 17| 37 | 45 | 28
Futaba 9C |FM |50 | 55| 72.3| 82.3| 64.9
Futaba 14MZ |PPM8 | 4 | 6| 39 | 41 | 22.5 (1)
Hitec Eclipse7|FM |22 | 28| 42.6| 50.5| 35.8
JR 8103 |FM |10 | 14| 32 | 40 | 24
JR 9303 |FM |10 | 14| 32 | 40 | 24
JR 10X |FM |10 | 14| 32 | 40 | 24
Multiplex Evo9|FM |10 | 14| 32 | 40 | 24 (6)
|
|
PCM, DSM2, and FASST in Normal mode (Channel 6)
|
Transmitter |Receiver|MLF|MLL|MaxLF|MaxLL|Avg
--------------+--------+---+---+-----+-----+-----
ATX Stylus |92186Z |13 | 13| 27 | 27 | 20
Futaba T6EX |R606FS |17 | 17| 61 | 61 | 39
JR 8103 |649S |38 | 38| 58 | 58 | 53
JR 10X |649S |35 | 35| 55 | 55 | 50
JR X9303 |R921 |25 | 25| 47 | 47 | 36
|
|
PPM and Normal (Channel 6)
|
Transmitter |Receiver|MLF|MLL|MaxLF|MaxLL|Avg
--------------+--------+---+---+-----+-----+-----
Futaba 9C |PPM |32 | 32| 59.3| 59.3| 45.65
Futaba 14MZ |PPM8 | 3 | 3| 40 | 40 | 21.3
JR 8103 |PPM |16 | 16| 38 | 38 | 27
JR 10X |PPM | 8 | 8| 30 | 30 | 19
|
All times are in milliseconds.
MLF - Minimum latency to first change at receivers output
MLL - Minimum latency to last change at receivers output
MaxLF - Maximum latency to first change at receivers output
MaxLL - Maximum latency to last change at receivers output
Avg - Average of MLF, MLL, MaxLF, and MaxLL
|
(1) Using channels 4, 5, and 6
(2) Using channels 1, 2, and 6
(3) Deduced numbers from observed behavior
(4) Channels 4, 5, and 6 on 14MZ and channels 2, 5, and 6 on AR9000
(5) Subject to collective input slew rate limiting
(6) In PPM 8, JR channel assignments, HELIccpm model and NOT an IPD receiver

fogger

02-04-2008, 04:38 PM

Wow, no wonder my DX7 / AR7000 felt so much more locked in than my DX6 / AR6000 previously had :) , 2.6X lower average latency.

-Fog

BruceW

02-07-2008, 12:58 AM

This is interesting. I thought the JRX9303 and Spektrum DX7 used the same specs internally but it looks like the DX7 is tuned a little better by getting about 10ms better averages for latency.

Also, I thought the XPS system was supposed to be faster than what I'm seeing here.

Pinecone

02-07-2008, 08:31 AM

DX 7 = 7 channels of data. X9303 = 9 channels of data.

More data, more time for the data stream.

Also the X9303 will work at 2048 resolution versus 1024 for the DX7, so a extra bit per channel.

fogger

02-07-2008, 11:11 AM

Perhaps they should allow a user to inhibit unused channels to prevent them from transmitting on the 9303...

-Fog

DavidH

02-07-2008, 12:16 PM

I may be wrong. But I think the only channels that JKos checks is the 3 channels that would control the swash on a eCCPM heli.
Not sure what they are doing with the new radios. But in the past all the channels did not update every cycle. An example with be the JR 10X. You had to be aware of where you plugged the Aux plug for the gyro. Because it you plugged into a channel that did not update but every other cycle or more. Then it would screw up gyro operation.
Same thing with the new Futaba's, they grouped the channels different so the update cycle would have the groups updating at the same time.
When you see the 100% synchorization, they are talking about a group of channels operating at the same time.

David

Pinecone

02-07-2008, 01:11 PM

N11634

02-07-2008, 01:49 PM

....I think of all the wasted ms just standing there waiting for my model to repond to my radio.:bawl

DavidH

02-07-2008, 03:43 PM

I have not heard of radios not updating channels every cycle. That would have to be controlled in the PCM conversion as PPM has to send the entrie string.

Servo Sync on the Spektrum takes care of reordering the channels during the transmit to have like functions work closer. And the nice thing is, it is dynamic, so different models will have different channel order in the transmit stream.

It is the processor in the transmitter that controls the channel cycle update. If you used a JR 10 series radio, it was well known that some of the 10 channels didn't update every cycle. The primary control channels updated every cycle. But the AUX channels did not. Was not a problem till governors came into being used. Then it was crucial which AUX channel they were plugged into.

David

Finless

02-14-2008, 04:15 AM

Awesome! I was hoping Jkos would maintain these here.... Thanks Jkos!

I think this should be a sticky so I am making it one.

Bob

mjr_larkin

02-23-2008, 06:03 AM

10ms advantage to the dx7, can't help but wonder what more people think about that

Pinecone

02-23-2008, 08:31 AM

Mor channels, higher resolution, more data to transmit.

marchambault

05-30-2008, 12:43 PM

Going back to my last stastitics course (many, many years ago), there appears to be no statistically significant differences in the first 2/3 of the chart (sorted by minimum latency).

ie ... 20 ± 5 is not stastically different from 22 ± 5 as they "overlap".

Any chance we can get the results re-processed to include all channels available in each transmitter?

Ah Clem

06-06-2008, 11:10 AM

Any idea where the 12X figures into this?

JKos

06-06-2008, 11:31 AM

> ie ... 20 ± 5 is not stastically different from 22 ± 5 as they "overlap".

The bars are not error bounds. They are minimum at the lower end and maximum at the upper end.

> Any chance we can get the results re-processed to include all channels available in
> each transmitter?

My results incorporate the three channels used for the swash servos except those listed as "Normal swash mode". It would be a monumental task to go back through all the radios to capture every channel.

> Any idea where the 12X figures into this?

The 12X numbers are available in my thread on the otheRR site (http://www.runryder.com/helicopter/t172571p1/). Someone needs to keep the charts copied over to here up to date. ;)

- John

Ah Clem

06-07-2008, 01:36 AM

Jkos,

Thank you!