User Guide

Oxygen 88 User Guide  37
16,384 step resolution through combined Coarse and Fine messages
Most assignable MIDI controls, including those on Oxygen 88, operate with a resolution of 128 steps. Standard
MIDI CC messages that can be used universally between different MIDI devices are also limited to a resolution of
128 steps. However, the RPN/NRPN concept allows for a resolution of 16,384 steps by combining two 7-bit MIDI
messages into a 14-bit message (coarse + fine).
Hardware controller knobs or sliders that take advantage of the full 14-bit RPN/NRPN resolution are very
uncommon. To illustrate the concept and make the purpose of RPN/NRPN Coarse and Fine messages easier to
understand, we included a graphic describing how such a 14-bit RPN/NRPN control would operate (not supported
by Oxygen Series keyboards):
The RPN/NRPN coarse message divides the range of 16384 steps into 128 segments and activates them by
sending each segment's first value, while the RPN/NRPN fine message provides the 128 steps of resolution
contained in each of these segments.
Coarse
0
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
16,384
2
3
4
5
6
7
8
9
4
4
4
4
5
5
5
5
6
6
6
7
7
7
8
8
9
4
4
4
4
5
5
5
5
6
6
6
7
7
7
8
8
9
4
4
4
4
5
5
5
5
6
6
6
7
7
7
8
8
9
127
2
127
127
1
3
Fine
Fine
Fine