No Midi input from M-Adio Keyboard

Does it show up in Preferences-MIDI Devices? When you plug in the USB cable, does Windows recognize it? If not, make sure you have the right driver for your operating system including whether its 32 or 64 bit. The 88es is a MIDI device, not a control surface.

 Have you enabled the input echo button on the track? 

Double check that you are transmitting and receiving on the same midi port and channel that Sonar is expecting to receive & transmit on for the selected track. (I've been burned by a wrong channel setting once or twice before.)

I am still a bit confused.

Are you trying to use it as a control surface, or as a midi controller?

And, let's make sure it is detected by Windows.  I have NO idea what operating system you are running (please add your system specs to the signature section of your forum profile), but anyways, right-click in Windows Explorer on Computer, then click on Manage, and then click on Device Manager.  Once that opens, scroll down if needed to 'Sound, Video, and Game Controllers' and expand that.  You should see the M-Audio midi controller there.  Double-click on it to open its properties page, and make sure Windows thinks it is operating normally.

If Windows does not detect it, that means no drivers are loaded into memory for it, and you have some driver installation debugging to do.

Once you have THAT sorted out:

If you are trying to use it as a midi controller, it should show up as available to be checked for midi input in the midi devices section of Preferences.

Further, Windows should have a midi activity indicator that lights up in the system tray when you press notes on the M-Audio keyboard.  That indicates that Windows is detecting midi activity.  If there is none detected, you have some M-Audio midi controller debugging to do - perhaps a re-install of its drivers.

Once you have THAT sorted out:

I have no idea of how to further guide you, until you post back and let us know your system specs AND the manner in which you are trying to send MIDI data to Sonar - (as note events through pressing keys and such, or as a control surface, which requires setting up through ACT).

I look forward to hearing back from you on the requested information, so that we can collectively try to help you resolve your issues here.

Bob Bone