Roland RS-70 业主指南

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页码 196
 
129
 
Performing with an 
external MIDI device
 
Performing with an external MIDI device
 
About MIDI
 
MIDI (Musical Instrument Digital Interface)
 
 is a standard 
specification that allows music data to be exchanged among 
electronic musical instruments and computers. By connecting MIDI 
devices that are equipped with MIDI connectors, you can play 
multiple instruments with a single keyboard, have multiple MIDI 
instruments perform in ensemble, program the settings to change 
automatically to match the performance as the song progresses, and 
more.
If you mainly use the RS-70 as a standalone keyboard instrument, 
you may really not need to know much at all about MIDI. However, 
the following MIDI-related information is provided so you can play 
the RS-70 using an external MIDI device, or master other advanced 
techniques.
 
MIDI connectors
 
The RS-70 has the following two types of MIDI connectors.
 
fig.r10-01
 
MIDI IN Connector
Performance messages from an external MIDI device are received 
here. When the RS-70 receives MIDI messages, it will produce 
sound, change the sound it’s using, or perform other operations.
MIDI OUT Connector
This connector transmits MIDI messages to external MIDI devices. 
The RS-70’s MIDI OUT connector is used for sending the 
performance data of the keyboard controller section, as well as the 
data used for saving various settings.
 
MIDI channels and multitimbral sound 
generators
 
MIDI transmits many types of data over a single MIDI cable. This is 
made possible by MIDI channels. MIDI channels allow messages 
intended for a given instrument to be distinguished from messages 
intended for another instrument. In some ways, MIDI channels are 
similar to television channels. By changing the channel on a TV 
receiver you can view the programs of different stations. This is 
because the television set has thus been directed to selectively 
display only the information being transmitted by a particular 
station. In the same way, MIDI also allows a device to select the 
information intended for that device out of the variety of 
information that is being transmitted to it.
 
fig.r10-02.e
 
MIDI uses sixteen channels, numbered 1–16. Normally, receiving 
devices should be set so they receive only the channels they need to 
receive.
 
Example:
 
Set the RS-70 to send on Channel 1 and Channel 2, then set sound 
module A to receive only Channel 1, and sound module B to receive 
only Channel 2. With this setup, you can get an ensemble 
performance, with, for example, a guitar sound from sound module 
A and bass from sound module B.
 
fig.r10-03.e
 
When used as a sound module, the RS-70 can receive on up to 
sixteen MIDI channels. Sound modules like the RS-70, which can 
receive multiple MIDI channels simultaneously and play different 
sounds on each channel, are called “
 
multitimbral sound modules
 
.”
 
MIDI messages used by the RS-70
 
MIDI uses various types of messages to transmit a wide variety of 
information. MIDI messages are broadly divided into two different 
categories, those handled through individual MIDI channels 
(Channel messages), and messages that are not related to separate 
channels (System messages).
The RS-70 mainly uses the following MIDI messages.
 
Channel messages
 
These are messages used for conveying what is happening in a 
performance. These comprise the bulk of MIDI messages.
 
Note On
 
This message is sent when a key is pressed. A Note-on message 
contains the following three types of information:
 
Note-on:
 
A key has been played.
 
Note number:
 
Which key was played
 
Velocity:
 
The amount of force (velocity) used when the key 
was played.
The Note Numbers fall within the range of 0–127, with middle C 
(C4) as number 60.
 
fig.r10-04.e
 
Note Off
 
This message is sent when a key is released. When a Note-off 
message is received, the relevant note will be turned off. A Note-off 
message contains the following three types of information:
 
Note-off:
 
A key was released
 
Note number:
 
Which key was released
 
Velocity:
 
The force (velocity) used during release of the key.
The cable from the antenna carries the TV
signals from many broadcast stations.
The TV is set to the channel of the station
you wish to watch.
Station B
Station A
Station C
MIDI OUT
MIDI IN
MIDI THRU
MIDI IN
Receive channel: 1
Receive channel: 2
Sound
Module 
A
Sound
Module 
B
Transmit channel: 1, 2
MIDI keyboard
C4
C3
C2
C5
C6
G9
36
48
60
72
84
127
C-1
0
Note name
Note number
RS-70_e4.book 129 ページ 2003年8月18日 月曜日 午前9時47分