Roland VS-1680 - Manual (Page 4)

This section explains the basic concepts of MIDI, and
how the VS-1680 handles MIDI messages.
What is MIDI
MIDI stands for Musical Instrument Digital
Interface
. It is a worldwide standard that allows elec-
tronic musical instruments and personal computer to
exchange musical performance data and messages
such as sound selections. Any MIDI-compatible device
can transmit musical data (as appropriate for the type
of device) to any other MIDI-compatible device,
regardless of its manufacturer or model type.
MIDI connectors
MIDI messages (the data handled by MIDI) are trans-
mitted and received using the following three types of
connectors. On the VS-1680, MIDI OUT and MIDI
THRU are handled by a single connector, which can
be switched to act as the desired connector. (Owner’s
Manual p. 129)
MIDI IN:
This receives MIDI messages from exter-
nal MIDI devices.
MIDI OUT: This transmits MIDI messages from the
VS-1680.
MIDI THRU: This re-transmits all MIDI messages that
were received at MIDI IN, without mod-
ifying them.
MIDI channels
MIDI is able to send information over a single MIDI
cable independently to two or more MIDI devices.
This is made possible by the concept of MIDI channels.
You can think of MIDI channels as being somewhat
similar in function to the channels on a television. By
changing the channel of a TV set, you can view a vari-
ety of programs being transmitted by different broad-
cast stations. This is because data is received only from
the transmitter whose channel is selected on the
receiver.
In the same way, a MIDI device whose receive channel
is set to “1” will receive only the data being transmit-
ted by another MIDI device whose transmit channel is
also set to “1.”
MIDI messages
The VS-1680 uses the following types of MIDI mes-
sage.
Note messages:
These messages are used to play notes. On a keyboard,
these message transmit the key (note number) that
was pressed, and how strongly it was pressed (veloci-
ty). On the VS-1680, these messages are used when
you use a MIDI sound source to play the metronome
sound.
Program Change messages:
These messages are for the purpose of selecting
sounds, and contain a program number of 1–128. The
VS-1680 uses these messages to select scenes and
effects. (Owner’s Manual p. 138, 139)
Control Change messages:
In general, these messages are used to transmit infor-
mation such as vibrato, hold, and volume etc., that
makes a performance more expressive. The various
functions are differentiated by a controller number
from 0–127, and the controller number is defined for
each function. The functions that can be controlled on
any given device will depend on that device.
On the VS-1680, these messages are used in a
completely different way than on most instruments
;
they are used to control mixer parameters.
Exclusive messages:
Unlike note messages and control change messages,
exclusive messages are used to transmit settings that
are unique to a particular device. On the VS-1680,
exclusive messages can be used to control mixer para-
meters (in the same way as control change messages).
Normally, control change messages are easier to han-
dle, so they should be used rather than exclusive mes-
sages. Exclusive messages intended for different units
are distinguished by their Device ID, rather than by
MIDI channel. When exclusive messages are to be
transmitted or received, you must set the Device ID of
both units to a matching setting.
MIDI implementation chart
MIDI allows a variety of electronic musical instru-
ments to communicate with each other. However it is
not necessarily the case that all devices will be able to
communicate using all types of MIDI message. They
can only communicate using those types of MIDI mes-
sage that they have in common.
Each owner’s manual for a MIDI device includes a
MIDI Implementation Chart. This chart shows you at a
glance the types of MIDI message that can be transmit-
ted and received. By comparing the implementation
charts of two devices, you will be able to see the types
of message with which they will be able to communi-
cate.
About MIDI
4