Die deutsche Bedienungsanleitung ist glaube ich nicht aktuell, nimm lieber die Englische:
Hier ein Auszug aus dem Manual Seite 28/29:
The DUAL KB feature allows for playing and controlling either the entire Panel B, or one of the Panel B sound engines from an external keyboard connected to the mIDI input of the Nord Stage 3. This can be handy in live situations where a secondary keyboard can be used as a controller for parts of the Nord Stage 3, on a per-program basis.
Dual Kbd Style
By default Dual Kbd Style is set to Organ, meaning that a connected mIDI keyboard sending on the Dual KB channel will control the Panel B organ section. To change this to Panel, Piano or Synth, press down on DUAL KB (Shift + Panel B) and make a selection using the dial.
When a sound engine is in Dual KB mode its KB Zone LEDs will all be unlit – indicating that it is not controlled from the internal keyboard and that it is unaffected by any active split points. With Dual Kbd Style set to Panel, keyboard zones and split points are handled as normal
With Organ, Piano and Synth Dual Kbd Style the Nord Stage 3 keyboard still controls all sound engines on both Panel a and B, except for the one that has been selected for external control. With Dual Kbd Style
set to Panel, the Nord Stage 3 keyboard always controls Panel a only, regardless of Panel focus.
The Dual KB setting is stored with a Program, along with all other panel settings.
M The MIDI Channel for the Dual KB feature is set in the MIDI Menu on the Nord Stage 3. Read more on this on page 56.
aBoUT PEDaLS aND oTHEr CoNTroLS IN DUaL KB
When Dual Kbd Style is set to Organ, Piano or Synth the Nord Stage
3 pitch stick, and sustain pedal will affect the selected sound engine according to how the respective panel controls are set. If SUSTPED and PSTICK are turned off on the panel, these are only controlled by incom- ing mIDI on the Dual KB channel.
In Panel mode the Nord Stage 3 pitch stick and sustain pedal never have effect in Panel B regardless of panel settings.
The local Control Pedal, modulation Wheel and aftertouch do not im- pact morphs assigned to sound engines that are in Dual KB mode.
M A Swell pedal connected to the Nord Stage 3 will also affect an externally played Organ in Dual KB mode. This is to accomodate “dual manual” organ setups.
all parameter controls for Panel B are still accessible from the Nord Stage 3. This means that organ drawbars, Synth settings etc. can be adjusted from the Nord Stage 3 even if the sound is being played from the external keyboard.