Lexicon MPX 1 V1.10 - MIDI IMPLEMENTATION DETAILS Midi Implementation Manual page 11

MPX 1 V1.10 MIDI Implementation Details
For example, for the MPX 1, part of the tree looks like this:
System Control level
A B C
| | |
0 - Program
0 - Pitch
0 - Detune (M)
1 - Detune (S)
2 - Detune (D)
3 - Shift (M)
1 - Chorus
...
2 - EQ
...
3 - Modulation
...
4 - Reverb
...
5 - Delay
...
Initially, the MRC display would simply show the name of the connected product which it retrieves by
requesting the Parameter Type at the top of the tree. Once the Parameter Type is known, a request is sent
for a description of the parameter which would include the name of the parameter (in this case "MPX 1",
the top level parameter). The description also includes a minimum and maximum value for the parameter
which would be used to select branches to drop down into.
This currently has a maximum value of 1 so requests are made for the Parameter Types at System Control
Addresses 0 and 1. Requests are sent for descriptions of the two Parameter Types. The name strings in
the returning messages are used to display the choices, one over each fader: "Program" and "System".
When a labeled fader is moved, the MRC isends a Parameter Data Message to the connected system
followed by a request for the Parameter Display Message for the parameter. This produces a formatted,
text version of the current parameter value. Pressing the button drops you to the next level. In this example,
let's assume we've selected the "Program" branch. In the above diagram "Program" has 6 items under
it: Pitch, Chorus, EQ, Modulation, Reverb and Delay. Moving the "Program" fader we would see "Pitch",
"Chorus", "EQ", "Modulation", "Reverb" or "Delay" displayed. The strings would be acquired by setting the
"Program" parameter value and requesting a Parameter Display message.
If the "Program" button is pressed, the system requests the Parameter types of the first four branches
under "Program": "Pitch", "Chorus", "EQ" and "Modulation". The names from each description are
displayed over the four faders. Pressing the MRC's PAGE button would get the next four items if available,
eventually wrapping back around to the first four. As the faders are moved, the Parameter Data Message
is sent and Parameter Display message is requested to display the selection.
The previous process is repeated until the "Branch" bit of the "Control Flags" of a parameter description
is encountered set for 0. (Parameters with that bit set to 0 actually change the operation of the system and
signal the end of a branch. The previous parameters only provide navigation through the tree.)
8
D E F
| | |
0 - Mix
1 - Level
2 - Tune
3 - P Dly
...
...
...
G H I
| | |
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