11
SysEx Explained
System Exclusive (SysEx) messages were defined in the MIDI specification to allow individual devices to have individual control via MIDI. The
format of SysEx messages allows for virtually any function to be performed via MIDI—so long as the receiving device is able to translate the
message and act accordingly. This allows devices to send audio sample memory data, memory dumps, controller settings, and much more.
It also allows the controllers of one device to be controlled by another.
It is not possible to program your own specified SysEx message into the M-Audio O
2
. However, several useful Sys Ex messages are pre-
programmed into the keyboard. They can be accessed by assigning the appropriate MIDI CC to a controller (see Appendix B).
It should be noted that a SysEx message is not transmitted on any specified channel. All SysEx messages contain a Device ID, which is used to
single out devices to respond to the SysEx message. All other devices are ignored. If you are using a SysEx message on the M-Audio O
2
, the
Global Channel is ignored. When you press the CHAN key, instead of entering a channel for the controller, you will enter a Device ID instead.
This is indicated by the fact that the LED displays a 3-digit number, not a 2-digit number proceeded by a “c.”
Device ID’s run from 00 to 127. 127 is the default device number setting on the M-Audio O
2
. This setting transmits the SysEx message to all
devices.
Although it is not possible to program the controllers of the M-Audio O
2
with your own SysEx messages, there are software applications that
can receive a MIDI input signal and transmit a different, user-specified message. You can program your SysEx messages into the translator
software, and then translate the incoming data from the keyboard to your SysEx, depending on the controller you are using.
General Trouble-Shooting
Here are answers to common questions you may have, using your M-Audio O
2
keyboard:
Problem 1: My keyboard suddenly stopped working after having performed fine since installation.
Solution 1: Switch off the unit and let it sit for 10 seconds. Then restart your computer and try again. If the problem persists you may have to
reinstall drivers for the unit.
Problem 2: I have plugged a sustain pedal into my keyboard, but it works the wrong way around.
Solution 2: The polarity of the sustain pedal is calculated by the keyboard when it is powered up. On power up, the sustain pedal is assumed
to be in the OFF position. So if you want the sustain pedal to be off when it is not depressed, make sure the pedal is not depressed when you
power up.
Problem 3: When I press a key, there is a delay before I hear any sound.
Solution 3: This delay is known as latency. Latency with MIDI signals is due to the software application you are using. MIDI data is simply
control data. The MIDI data is read by your software. The software then completes a large number of complex calculations in order to produce
the sound you hear–all this takes time.
We strongly recommend a proper soundcard. Refer to www.m-audio.com for a selection of USB, PCI and FireWire audio cards. If you already
have an adequate sound card, try reinstalling the latest drivers for the sound card, or try reducing the buffer sizes of the audio drivers.
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