Hi,
I have been using this keyboard for quite some years and loving it. 
Was earlier using a Midi controller for this job but it died. So i want to use these settings on the A-800 pro instead, atleast till i order a new controller.
 
DAW - Logic X. 
 
a. Route faders S1-S9 to Modwheel / Expression
Let's say S8 to modwheel and S9 to expression.
 
I am unable to figure out what Input and Output settings to choose in the Editor because it doesn't come with a manual (ok I didn't search enough). 
 
PS : First post here. Greetings ! 

Hi, welcome to the forum. I don't have Logic, but the best way (safest way) would be this:
 
1. In the A-Pro Editor, go to Option -> MIDI Device, and select "A-PRO 2" from the Input port and "A-PRO" from the Output port.
2. Click on the S8 slider in the editor and then set up the options like this (ignore the "P2" in the upper left corner): http://i.imgur.com/wgG0dvW.png
3. In Logic, select "A-PRO 1" (if it's not there you should check the MIDI device configuration page in Logic) from the MIDI track's input drop-down. Although "All inputs" or "None" or "omni" or whatever that means the same also works, I recommend choosing A-PRO1 for some complicated reason.
 
If you're wondering why you need to choose "A-PRO2" at Step 1 and "A-PRO 1 (Port 1)" at Step 2 & 3, it's because modulation data, as well as musical data like note and velocity information, should go through the A-PRO 1 port and flow into the MIDI track to control the modulation of a synth that track uses, while other controller data should use the A-PRO2 port to control various parameters of Logic (e.g. faders, pan controls in the mixer).
 
Hope that helps (hope I'm not wrong )

thanks a lot !  let me try that 

it worked ! thanks a lot ! 
 
I did exactly what you said and have now assigned S8 to CC1 and S9 to CC11

You're welcome! 
 
(I've just noticed a small error in my post so I corrected it )

Hello W  (do you watch Alton Brown on the Food Network, by chance?)
This is also a good resource for doing programming on your 800
 
http://forum.cakewalk.com/UPDATED-Configuring-Your-APro-to-Work-WithWithout-ACT-m2181430.aspx