RunRyder RC
 2  Topic Subscribe
WATCH
 1 page 1996 views POST REPLY
Scorpion Power Scorpion Power
HelicopterRadio - Futaba FASST › R6008HS or R6014HS High speed mode?
12-28-2009 11:52 PM  7 years agoPost 1
stevehof

rrApprentice

Oceanside, CA, USA

My Posts: All  Forum  Topic

I'm looking for confirmation that the R6008HS and R6014HS receivers will only work in 'high speed' mode (7ms refresh) with the 10CG or 8FG? I see they will work with the 12FG but I'm assuming you aren't going to get the 7ms refresh, correct? - Thanks

PM  EMAIL  GALLERY  Attn:RR  Quote
12-29-2009 12:30 AM  7 years agoPost 2
Thomas L Erb

rrKey Veteran

Alliance ohio

My Posts: All  Forum  Topic

The 6108hs and 6014hs will work the same with any of the 2048 res radios or modules when in HS mode. The HS mode is the refresh rate that the rx talks to the servos. this is why you must have a digital servo on channels 1-6 in HS mode. You can also get the same refesh rate with the r6106hfc in all Fasst radios in 1024 res ( 7 channel mode)

Tom

PM  EMAIL  GALLERY  Attn:RR  Quote
12-29-2009 12:36 AM  7 years agoPost 3
stevehof

rrApprentice

Oceanside, CA, USA

My Posts: All  Forum  Topic

So when folks are saying the 10CG is faster than the 12FG they are actually referring to the HS receiver that comes with the 10CG and not a signal processing speed difference between the two transmitters?

PM  EMAIL  GALLERY  Attn:RR  Quote
12-29-2009 01:47 PM  7 years agoPost 4
Smok

rrApprentice

Antwerp, Belgium

My Posts: All  Forum  Topic

As far as I have read these discussions, it refers to the 10CG
low latency when running in eCCPM mode - ie. how fast the 10CG
can calculate and execute the "stick-to-eCCPM-to-servo" conversion.
Older radio tend to incur a latency penalty between straight
stick-to-servo operation (like with a simple airplane) and they slow
down when using eCCPM mix, likely due to the needed calculations.

Separately to that - the HS mode is only a latency difference
between the Receiver and servo, due to different signal frequency
( an HS needs a digital servo ). Analog mode signal rate
is 50 Hz while digital is around 300 Hz ( times per second ).
Using HS mode with an analog servo is a sure way to fry it.

The HS mode is similar to a gyro-servo interaction - practically
no matter how fast servo you take, there will be a tail wag
if the gyro runs in analog servo mode (for all but very heavy helis ).

Analog servo mode sends a position signal 50 times a second
while a digital mode sends it 270 or 330 times a second
(or over 500 times a sec in case of Futaba 611 and 520 gyros).

That 200Hz difference will amount to around 0.02 seconds
less latency saved by the HS signaling mode.

But eCCPM performance is not only related to HS mode
- also to the stick-to-Tx-signal calculation latency by the Tx.

PM  EMAIL  Attn:RR  Quote
12-29-2009 02:56 PM  7 years agoPost 5
stevehof

rrApprentice

Oceanside, CA, USA

My Posts: All  Forum  Topic

Thanks

for the detailed reply!!!

PM  EMAIL  GALLERY  Attn:RR  Quote
12-29-2009 03:06 PM  7 years agoPost 6
bbaxter

rrApprentice

Central Illinois

My Posts: All  Forum  Topic

ANY Futaba FASST transmitter, or transmitter with FASST module, will work with the "HS" receivers in either regular or HS mode. With HS mode, latency is not reduced by any noticeable amount, but holding power is greatly increased because the servos get position commands much more often than in "regular" mode. This is why you must use digital servos, only, when operating in HS mode. Only digital servos will respond to the higher-frequency command signals.

PM  EMAIL  Attn:RR  Quote
12-29-2009 04:46 PM  7 years agoPost 7
Smok

rrApprentice

Antwerp, Belgium

My Posts: All  Forum  Topic

I would somehow agree that "with HS mode, latency is not reduced by any noticeable amount" because the max latency difference of around 16 msec is hardly noticeable - but it's still there. It becomes somehow noticeable with the very fast top of the line servos ( say BLS253, BLS451 and the likes ) and when paired with a very low-latency transmitter.

With a similar technology for the car radios - the HRS mode - the lower latency is definitely noticeable when paired with BLS451 and 5-cell RX battery ( with HRS the car steering is instant and "locked-in" ) - or even more with a 2-cell unregulated LiPo ( not officially supported by Futaba for BLS line - I guess at least "not yet" - I see it might be coming down the line, IMHO ).

Then I would be quite curious what is the benefit of HS for holding power - would the holding force increase because of HS mode and why ? A digital servo will try to hold the position if there is no Rx signal saying to the servo to change it, so I would rather understand that the max holding force would not change, as it's the function of motor power/moment and gear ratio, not signaling rate, isn't it ?

If we look at the overall latency, servo speed matters the most for large deflections ( as it will take max time to go say from -60deg to +60deg ). But if we look at very minor corrections ( say 5 degrees ) then the servo can move in 1/10th of the rated servo "speed" time - that would mean that for BLS451 it would take around 0.01 to move 5deg.

So, for this 5 degree change - if we add-up the HS latency of 7ms it totals 17ms, compared to 27ms for non-HS Rx to servo latency. That is usually hard to see but the feel is more locked-in and with instant correction.

Again comparing to HRS, which works similarly and for similar purpose - for car drivers it makes the difference if you turn or brake before the obstacle or into it. For planes/helis it is not so crucial, but still affects how fast corrections can be made.

Just my 5 eurocents ;-)

Smok

PM  EMAIL  Attn:RR  Quote
WATCH
 1 page 1996 views POST REPLY
Scorpion Power Scorpion Power
HelicopterRadio - Futaba FASST › R6008HS or R6014HS High speed mode?
 Print TOPIC  Make Suggestion 

 2  Topic Subscribe

Monday, October 23 - 4:23 pm - Copyright © 2000-2017 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online