It will depend on whether the keyboards will send and receive the Midi code for transposing, if so then just connect a Midi cable between the two, or to your device.
You can check in the keyboard manual to see if it is supported, (There is normally a Midi implementation chart in there, that will give you the information you require)
Bill
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English Riviera:
Live entertainment, Real Ale, Great Scenery, Great Beaches, why would anyone want to live anywhere else (I�m definitely staying put).