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Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 8:11 am
by pnedic
Hi

I'm using OpenTX v2.0.17 for programming of my Turnigy9X TX. I know that BEFORE I started to use openTX (or previously Companion9x), there was, in original (factory) firmware, option to change between PPM an PCM. Now, by using mentioned software, I do not see this option. Why ? Or there something has to be checked (which I didn't find) ?

I'm asking this because I have some other receiver, that (seem) works on PCM, unlike Turnigy which works on PPM. So I can not pair this additional Rx to my Turnigy TX. Well I'm not sure is this problem (PPM/PCM) or something else.

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 8:36 am
by Kilrah
PCM was proprietary, and only applied to XX-MHz band receivers.
2.4GHz is a whole different thing, and each brand has its own protocol so apart from "compatible" receivers you can't mix brands.
Could help if you mentioned what receivers you actually have.

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 8:46 am
by pnedic
Kilrah, thanks for reply !

The "other" receiver I have is some chineese receiver got from a RTF model. But transmitter and receiver looks very good and solid (9 chanels !) Brand is "EDOMODEL". On Rx it is written PCM.

PCM, as I know, stands for Pulse Code Modulation (PPM=Pulse Position Modulation). Is the PCM proprietary or what ever, I respect for sure, but I think this is matter of type of used technology !

Why then Turnigy had (by factory settings) that option to choose PPM or PCM ? What for it is used ? If PCM is used for only MHz transmitters, how come it was present in Turnigy9X 2.4GHz transmitter ?

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 9:15 am
by jhsa
A few years ago the 9x radio was sold with a FM antenna on it. You know those old long methatlic antennas. That means you could use one of those FM modules that worked with PPM or PCM. Now the radio ships with a 2.4Ghz module and without antenna. They just never bothered to change the software...

That module and receiver you have, how long is the receiver antenna?

João

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:02 am
by pnedic
jhsa wrote:A few years ago the 9x radio was sold with a FM antenna on it. You know those old long methatlic antennas. That means you could use one of those FM modules that worked with PPM or PCM. Now the radio ships with a 2.4Ghz module and without antenna. They just never bothered to change the software...

That module and receiver you have, how long is the receiver antenna?

João
The Tx has 2.4Ghz antena as it can be seen on Hobbyking site. The antena on receiver is also 2.4Ghz - it's approx 31mm long.

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:10 am
by jhsa
The forget about all that PCM thing ;) :)

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:18 am
by pnedic
jhsa wrote:The forget about all that PCM thing ;) :)
OK, Thanks !

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:27 am
by jhsa
Does the module work with the radio?

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:35 am
by pnedic
@jsha
Tx has installed the 2.4GHz module with antenna. There is NO old antenna - only one antenna connected to the module.
Both Tx and Rx can be seen on link http://www.hobbyking.com/hobbyking/stor ... ware_.html
I hope when you see the link, you'll get the answer to your question.

That "the other receiver" is not turnigy. Here is the picture of receiver:Image

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:42 am
by jhsa
Ahhhh. that is the original module and receiver that come with the radio.. Then yes, it will work.. Just forget all that PCM talking ;)
But I was talking about that "EDOMODEL" receiver you mentioned.. That is what you want to know right?
That is the one that has PCM written on it, correct?
João

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:52 am
by pnedic
On the transmitter that came with this receiver (EDOMODEL) is written "Digital proportional R/C System". I do not use this transmitter. If you need picture of this transmitter I'll post it, but now I didn't in order to avoid cunfuse.

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:53 am
by pnedic
jhsa wrote: ...
That is the one that has PCM written on it, correct?
João
Yes ! I tried to match this receiver with turnigy9X transmitter ! And NO success.

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:53 am
by jhsa
If your receiver is similar to the one linked below, it might only work with a dedicated "EDOMODEL" RF module. Not with the turnigy module

http://www.rcgroups.com/forums/showthread.php?t=1912558

As Kilrah already explained on his post above, normally you can't mix brands on 2.4Ghz.
Each brand uses it's own protocol, that means, it won't work with other brands.
João

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 10:57 am
by pnedic
jhsa wrote:If your receiver is similar to the one linked below, it might only work with a dedicated "EDOMODEL" RF module. Not with the turnigy module

http://www.rcgroups.com/forums/showthread.php?t=1912558

João
Yes, this is (exactly) it !

Image

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 11:15 am
by jhsa
Yeah, I think that the edomodel plane's receiver will only work with this transmitter..
You could probably replace the receiver in the model with your own turnigy receiver.. This one will work with your turnigy radio..
João

Re: Turnig9X PPM/PCM on OpenTX

Posted: Tue Oct 06, 2015 11:36 am
by pnedic
OK, Thanks !