Elektron Musical Instruments

Please help 
i have a elektron MD.  I need to sync it to a roland xp80 synth sequencer.  I 
have set the synth to slave, and have midi out from the MD to the syth (in).  
MD is set to internal. Everything is OK except I get synth sounds from the drum 
machines pads and from the drum pattern as it plays.  How do I turn off the 
message getting to the MD from the synth?
thanks David Brown