Years ago, I had to Midi my guitar to the left hand of the keyboard. Later I used Mid to connect a Yamaha keyboard and a Kn5000.

If my memory still holds ---

Both units ( Master and the Slave) have 16 Midi channels. Each unit has an implementation chart in the manual. It shows you what is being used in each Midi channel. Your job is to connect the Master to the Slave using the same Midi channel.

I had to send messages to my Vocalizer, a Yamaha keyboard, and a Roland sound module, from my Kn5000.
That was a long time ago. The units today may be friendlier.

I hope this helps, John C.