Hi there!!!
 
I want to send a track to another track on sonar X3. Not to a auxiliar track.
I'll make myself clear. I saw a Pro Tools user sendind a track to another track and recording this on this second track the content processed at the first track.
Is it possible on sonar X3?
 
Thanks
 
Chris

Not in real time. The way to get the processed output of a track "printed" to another track in SONAR is to bounce it. There are very few situations in which this won't suffice; what are you trying to accomplish?
 
 

Midi or Audio? 
 
You can always solo the track and do a loop back recording in real time. Some interfaces have internal patching but most this would involve a short patch cable from output to input..careful with input echo and feedback loop..

Put a Sonitus compressor on the track, send to the side chain and monitor the side chain.

Monitoring a side chain input will play on the second track but it will not record to the second track.

I can't think of a use case where this would be essential. If you want to process a track with another track, you can simply feed it to a bus. Once you have the processing the way you want, bounce it. Or drag the audio to another track and do the same thing.

Just because Craig you cannot think of an application, does not mean it does not exist. It is a bit like clip gain changes actually changing waveforms. It IS handy and useful and fast.  And so is this too.  Faster. 
 
Fortunately Studio One allows any buss to be the input source for a new track. I have used it in a few situations.  I did not think at first it would be useful either but once you have used it then it all changes.
 
One is where a virtual synth may actually do something different every time you use it in real time. eg either driven from a pre recorded midi part or you fiddling with it live as it plays.
 
Another is where you might actually be mixing and making moves over some tracks or buses live while a mix is going down. It's handy to be able to route the main stereo buss back to a track as well.  You should be putting some human element into your mix ie making moves. It always sounds better to me.  It sounds better than sitting back and letting the computer do all the work.
 
You do have to be caerful ie digital feedback but it is easily avoided.

If you could send your Master bus to a track to record you can print the mix in real time ( like mixing down to a tape deck) and just export the audio from that track without waiting for the whole mix to bounce. I've done this with Tracktion and it's very handy and fast.

You can use a stereo out of your interface from the bus, patch it to a stereo input pair and use that as the input to the track. It involves an extra conversion but it does work

If you can route your main mix easily and internally back to a track you do not need to even export any audio from that track either.  The audio has already been recorded!  So it is even faster than that.  All you have to do is make sure you name the track correctly. Then you just go into the folder where your audio is and there it is.  No export required.
 
Patching signals externally is fiddly and not the best way as is doing a side chain thing as well.  Very roundabout way to achieve the result.
 
They should just put the feature in and be done with it.  But it is slightly dangerous and if you are silly you can get a feedback loop.  So I can sort of see why too they don't do it.  But then again a hammer in the wrong hands can be dangerous too but in the right hands an amazing tool.
 
The main advantage of this feature is when you get involved somehow with either a virtual instrument or a mix while it is playing.  (just like the old days!)  Hey think of all those fellas standing around making moves when they mixed Dark Side of the Moon.  I believe many had their hands on the mixing console at some point.