MIDI BASICS - MIDI MODES - PART 4

MIDI BASICS MIDI MODES

OMNI ON and OFF is another important element of MIDI. In OMNI OFF Mode, the receiver will accept Voice Messages exclusively on the selected channel.

In OMNI ON, the receiver will recognize the messages of all channels without discrimination.

In Fig 10, messages are sent on the channel 1 and 2 from the sequencer.

B receives only channel 2 messages, but C receives both 1 and 2 messages.

There are 4 receiver's modes with combination of OMNI ON/OFF and Poly/Mono as follows.

A. MODE 1 - OMNI ON, POLY
Voice Messages are recognized in all voice channels and assigned to voices polyphonically,

B. MODE 2- OMNI ON, MONO
Voice Messages are recognized in all channels, and control only one voice monophonically. One sound is emitted.

C. MODE 3- OMNI OFF, POLY
Voice Messages are recognized in the Channel Matched to the receiver's channel only, and are assigned to voice polyphonically.

D. MODE 4- OMNI OFF, MONO
Voice Messages are recognized in the channels N thru N + M — 1 , and assigned mono-phonically to voice 1 thru M, respectively. The number of voice M is specified in the MONO Mode Message sent from the transmitter.

This mode is useful for when a polyphonic keyboard controls several monophonic synthesizers.

Normally, when the power is first applied to a MIDI device, it defaults to Mode 1 (=OMNI ON, POLY Mode) allowing to accept messages of all channels.