Apple Logic Pro 9 - Manual (Page 1110)

The positions of events in the list only control the order in which they are sent—they are
not sent at specific times, nor with any delay between them.
The SysEx fader type is primarily designed to send MIDI System Exclusive (SysEx)
messages—messages that are exclusive to individual manufacturers’ MIDI devices. There
are a number of features in the SysEx fader window that facilitate the creation of SysEx
messages.
Note: SysEx faders can actually be used for any kind of MIDI event, making them handy
for sending ordered batches of messages, such as Mixer or control panel snapshots, with
one click of the mouse.
You can also specify SysEx as an Input definition, but this has limited usefulness because
the incoming message (presumably SysEx) must be very short in order to be recognized.
(Because SysEx messages can be of any length, Logic Pro must break them into small
packets to avoid interrupting other MIDI activities.)
An important thing to remember about the SysEx fader is that only selected events will
have their value altered by the fader value when the SysEx fader window is closed. Events
that are not selected will be sent exactly as they appear in the window.
The value shown in the Val column (of selected events) is altered, if normal MIDI events
(controllers, program change, aftertouch, and so on).
For SysEx messages, you can determine:
• Which bytes are altered
• The format (MSB/LSB, BCD, nibbles, and so on) of the value
You can also specify a checksum format, if necessary.
Working with SysEx Messages
There are two ways of entering SysEx messages in the SysEx fader window. One way is
to have the fader learn the SysEx string.
To teach the fader to learn a SysEx string
1 Click the MIDI In button at the top-left corner of the SysEx window. If the button is pressed,
it is ready to receive incoming MIDI data.
2 Alter the parameter on your device.
1110 Chapter 37 Environment Objects Reference