Yamaha PSR-225GM Owner's Manual - Page 94

MIDI FUNCTIONS MIDI is an acronym that stands for Musical Instrument Digital Interface, which allows electronic musical instruments to communicate with each other, by sending and receiving compatible Note, Control Change, Program Change and various other types of MIDI data, or messages. The PSR-225 can control a MIDI device by transmitting note related data and various types of controller data. The PSR-225 can be controlled by the incoming MIDI messages which automatically determine tone generator mode, select MIDI channels, voices and effects, change parameter values and of course play the voices specified for the various parts. MIDI messages can be divided into two groups: Channel messages and System messages. Below is an explanation of the various types of MIDI messages which the PSR-225 can receive/transmit. G Channel Messages The PSR-225 is an electronic instrument that can handle 16 channels. This is usually expressed as "it can play 16 instruments at the same time." Channel messages transmit information such as Note ON/ OFF, Program Change, for each of the 16 channels. Message Name Note ON/OFF Program Change Control Change PSR-225 Operation/Panel Setting Messages which are generated when the keyboard is played. Each message includes a specific note number which corresponds to the key which is pressed, plus a velocity value based on how hard the key is stuck. Voice number (along with corresponding bank select MSB/LSB settings, if necessary). Messages that are used to change some aspect of the sound (modulation, volume, pan, etc.). G System Messages This is data that is used in common by the entire MIDI system. System messages include messages like Exclusive Messages that transmit data unique to each instrument manufacturer and Realtime Messages that control the MIDI device. Message Name Exclusive Message Realtime Messages PSR-225 Operation/Panel Setting Reverb/chorus/DSP settings, etc. Clock setting Start/stop operation The messages transmitted/received by the PSR-225 are shown in the MIDI Implementation Chart on page 114. MIDI Terminals In order to exchange MIDI data between multiple devices, each device must be connected by a cable. The MIDI terminals of the PSR-225 are located on the rear panel. IN MIDI OUT MIDI IN Receives MIDI data from another MIDI device. MIDI OUT ....... Transmits the PSR-225's keyboard information as MIDI data to another MIDI device. 94 • Special MIDI cables (sold separately) must be used for connecting to MIDI devices. They can be bought at music stores, etc. • Never use MIDI cables longer than about 15 meters. Cables longer than this can pick up noise which can cause data errors.