Yamaha SY55 Product Manual page 171

( 4 ) Keyboard, sequencer and tone generator section.
note) * Note on messages from the keyboard are transmitted in the voice play
mode whether the receive and transmit channel are matched or not.
* Keyboard, sequencer and MIDI note on messages are separated.
Keyboard, sequencer, and MIDI control data, with the exception of
sustain, are not separated. Sustain is separated.
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