The Logic Environment
Environment block diagram
A block diagram of MIDI signal flow in Logic, which includes the hidden paths (sounds like Famous Five stuff).
Environment Faders can be used as MIDI Controllers, as well as other types of control.
F0 SysEx start
18 manufacturer ID (in this case Emu)
0F model ID (in this case Proteus)
dd device ID
55 special editor designator
01 parameter value edit
02 byte count (ie 2 byte pairs)
xx,xx parameter ID (LSB, MSB)
yy,yy parameter value (VAL,VAL)
Here is a example showing the Sysex string for the adjusting the LCD Contrast on an Emu Proteus 2000 (in Hex, and decimal).