Roland VS-890 - Manual (Page 3)

About MIDI
This section explains the basic concepts of MIDI, and ho\v the
VS-890 handles MIDI messages.
What is MIDI
МЮ1 stands for Musical Instrument Digital Interface. It is a
worldwide standard that allows electronic musical
instruments and p>ersonal 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 МГО1-
compatible device, regardless of its manufacturer or model
type.
MIDI connectors
МГО1 messages (the data handled by MIDI) are transmitted
and received using the following three types of connectors.
On the VS-890, MIDI OUT and МГО1 THRU are handled by a
single connector, which can be switched to act as the desired
connector. (Owner's Manual p. 161)
MIDI IN; This receives МГО1 messages from external
МГО1 devices.
MIDI OUT : This transmits MIDI messages from the
VS-890.
MIDI THRU: This re-transmits all МГО1 messages that were
received at MIDI IN, without modifying them.
MIDI channels
МГО1 is able to send information over a single МГО1 cable
independently to two or more МГО1 devices. This is made
possible by the concept of MIDI channels. You can think of
МГО1 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 variety of programs being transmitted by
different broadcast stations. This is because data is received
only from the transmitter whose channel is selected on the
receiver.
In the same way, a МГО1 device whose receive channel is set
to "1" will receive only the data being transmitted by another
MIDI device whose transmit channel is also set to "1."
MIDI messages
The VS-890 uses the following typ>es of MIDI message.
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 (velodty). On the VS-890,
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-890 uses these
messages to select scenes and effects. (Owner's Manual p. 172)
Control Change messages:
In general, these messages are used to transmit information
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-890, 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-890, exclusive
messages can be used to control mixer parameters (in the
same way as control change messages). Normally, control
change messages are easier to handle, so they should be used
rather than exclusive messages. 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 instruments 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 message 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 transmitted 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 communicate.