Cakewalk track to Roland autoaccompaniment

Hi ,
 
I have a track in cakewalk where I have recorded chords. I want these chords will be send to Roland keyboard which is set on Backing Mode, Sync Start. [Tried on GW-7 and GW-8]
 
When I start playing cakewalk, the accompaniment starts on roland but chord changing doesn't take place. If I manually play a chord on left hand it acts normally , i.e., changing chord is possible accordingly the accompaniment changes.
 
I have tried to set the channel of the track of cakewalk from 1-thru-16.
 
None of them brings the result.
 
Where I am making the mistake? Any help?
 
Thanks