As noted in the RD-2000 MIDI Implementation Chart, the RD-2000 can receive MIDI data (Recognized) on all MIDI channels 1 - 16: RD-2000 MIDI Implementation Chart
To activate (or deactivate) a Zone for MIDI reception, you can decide what Zone can receive MIDI from your External MIDI device by setting the PART SWITCH:
- press MENU and select SYSTEM
- go to the PART SW tab to select your Zone or MIDI Channel ready to receive MIDI
If you wish to save this setting, press the WRITE button while still in the System Menu, then select "OK" on the screen.
This video shows you how to activate an EXTERNAL Zone on the RD-2000:
Find more INFO here: