Doesn't really feel that it harms the system or do you think I should get to the bottom with this?

 
Ignore it, unless you see a problem surface later on.  There's a lot going on with that Clavinola.  It's a full MIDI workstation in its own right.  What you're seeing in the MIDI In/Out Activity may be annoying, but I believe it is harmless.
 

• If it were a MIDI loop, you'd be seeing some odd behavior ('frozen' MIDI meters in the Track View; 'echoing' notes from Local On at the Yamaha keyboard).
• It is possible that some knob, slider, or control on the Yamaha is intermittent, or has some dust in it.  Sometimes, controls like that will transmit continuously.  I doubt this is it, because that control would always be the first message 'learned' in your MIDI Learn procedure (detailed above).
• If it's 'active' sensing' messages [FE], there's not much you can do about it easily.
• If it's MIDI Clock pulse [F8], then you can turn off Internal tempo transmission at the Clavinola (usually, the default setting).  That is, unless you're using it as your 'master' MIDI Clock source for Sonar.  I stumbled across an interesting note in the Clavinola manual: The MIDI clock resolution is an astounding 1920 pulses every quarter note.

 
That is extremely fine resolution (if it's not a typo).  That would certainly explain the 'steady red light'.  If I had to guess, I'd say that it's your internal MIDI clock on the Clavinola that's the culprit here.  Again, probably harmless, but it could be contributing to some unnecessary MIDI data overhead, if you're not using it for anything.

Thanks again for your explicit response! The Clavinova, a far as I can see, only transmits midi notes, no aftertouch nor wheels nor pitchbend. It's a good piece of furniture I can have my computer screens on it as well as the loudspeakers and typewriter keyboard underneath. The weighed keyboard is good for grand piano playing, Its sound from within are useless. Many words about that.
Turning the Clavinova off immediately turns off the steady red light.

I can't get poly aftertouch to work with Z3TA. I have a CME XKey37 and poly aftertouch works on all of my apps that support it-but does not seem to work with Z3TA. The Z3TA recognizes the channel aftertouch though. 
 
Does anyone know for sure that the Z3TA supports poly aftertouch? I see "PolyAft" in the Matrix Control list but it does not respond to poly aftertouch.
 
I will be very disappointed if I spent $20 for an app that does not do what it is supposed to do from a company that does not provide it's customers any technical support or way of contacting them.
 
Thanks for any help

Bob("b" lots)
Have you tried sending the Poly After Touch to an obvious destination?
 
Is this stand alone or inside a DAW and if so which one?  SONAR filters After-touch messages by default it needs to be enabled in the Midi Preferences.
 
The link below will take you to the front page of the problem reporting page.  This is the method provided by Cakewalk for customers to contact their technical support team directly.
The Problem Report Form for Cakewalk Software
 
Making this statement somewhat incorrect. 
 

Bobbbbbbb_etc
 
a company that does not provide it's customers any technical support or way of contacting them.
 
 
 
[/quote
 
 

Thank you for your quick response.
 
Yes. I have connected PolyAft to Oscillators/All Ocillators/Pitch. I figure that pitch is the easiest to detect changes in modulation. I can definately hear the difference when I use, ChanAft or Mod wheel, but not when using PolyAft. 
 
I'm just using Z3TA+, all by itself with no other apps running, and the XKey37 connected as usual to the USB port on my iPadMini2.
 
I went to the Problem Report Form but the Product drop-down would not open to show the list of products and I cannot use the form unless a product is selected. 
 
Hopefully there is a solution to getting poly aftertouch to work with Z3TA+.
 

Just adding a couple more details...
 
I know when, or if, my Xkey is sending poly or channel aftertouch because the XKey Plus app lets me choose one or the other. I typically leave it set to poly aftertouch, because I have little need for channel aftertouch. I seek out ios synth apps that support poly aftertouch. From all appearances, it looks like Z3TA+ is supposed to support poly aftertouch and is the reason I spent $20 on it.
 
For trouble shooting sake, if I can hear changes when modulating channel aftertouch, I ought to be able to hear the changes with poly aftertouch (but per key).
 
Thanks for any help

Posting just to fix the frontpage formatting.
 
bobobbbboobbbbooobbb... your username is too looooollooooollooooong.
 
I believe you can edit it in your profile.
 
Welcome to the forum.

I could not find any place in the User Control Panel to change my user name. If its a problem, guess I could sign up again with another user name.  

the name change function is here https://www.cakewalk.com/My-Account/Manage

Thank you. I have successfully shortened my user name.