Adding Bass Pedals to kn 6000

I am trying to add my midi bass pedals to my kn6000. I have used them with other instruments with no problems and have a lot of experience using them with a Hauptwerk/Paramount 310 setup. So far I have no success at all with the Kn and would appreciate any information. They are one octave and currently set to transmit on midi channel 3. I have connected via I standard midi cable and set the KM midi to bass pedals. The switch at the back is set to midi and I have experimented in the mixer screens. All I get so far is a dull thud sound with no sustain.