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Dave Smith Instruments PROPHET 12 KEYBOARD User Manual

Page 71

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61

Prophet 12 Operation Manual

Appendix D: MIDI Implementation

NRPN Messages

The Non-Registered Parameter Number (NRPN) MIDI messages are

used to transmit and receive both global and program parameters. They

are transmitted when MIDI Parameter Send is set to NRPN in Global,

and received when MIDI Parameter Receive is set to NRPN in Global.

The messages are handled in standard MIDI format using the NRPN CC

commands in running status byte format. Below is the format used for

transmitting a NRPN parameter.

Transmitted NRPN Messages

Status

Description

1011 nnnn

Control Change

0110 0011

NRPN parameter number MSB CC

0vvv vvvv

Parameter Number MSB

0110 0010

NRPN parameter number LSB CC

0vvv vvvv

Parameter Number LSB

0000 0110

NRPN parameter value MSB CC

0vvv vvvv

Parameter value MSB

0010 0110

NRPN parameter value LSB CC

0vvv vvvv

Parameter value LSB

The parameter number can be found in the two tables below, one for

Global parameters, and the other for Program parameters. The parameter

numbers and the parameter values are broken into two 7-bit bytes for

MIDI transmission; the LSB has the seven least-significant bits, and the

MSB has the seven most-significant bits, though in most cases the MSB

will be zero or one, and never more than two.

When receiving an NRPN, all messages do not necessarily need to be

transmitted, since the synth will track the most recent NRPN number,

though it is usually good practice to send the entire message above.

Once an NRPN is selected, the synth will also respond to NRPN Data

Increment and Decrement commands, which some controllers utilize.

Finally, it responds to one RPN (Registered Parameter Number)

command, the RPN/NRPN Reset command, which can be handy for

resetting the currently selected parameter to a known state.