DIN EN 63035-2018 MIDI (Digitale Schnittstelle fur Musikinstrumente) Festlegung 1.0 (Gekurzte Ausgabe, 2015) (IEC 63035:2017);
Englische Fassung EN 63035:2017.
4.3 Message types
4.3.1 General
Messages are divided into two main categories: Channel and System.
4.3.2 Channel messages
A Channel message uses four bits In the Status byte to address the message to one of sixteen MIDI channels and four bits to define the message (see Annex A). Channel messages are thereby intended for the receivers in a system whose channel number matches the channel number encoded into the Status byte.
An instrument can receive MIDI messages on more than one channel, The channel in which it receives its main instructions, such as which program number to be on and what mode to be in, is referred to as its “Basic Channel”. An instrument may be set up to receive performance data on multiple channels (including the Basic Channel), These are referred to as Voice Channels. These multiple-channel situations will be discussed in more detail later (see 4.5).
There are two types of Channel messages: Voice and Mode.
• VOICE: To control an instrument’s voices. Voice messages are sent over the Voice Channels.
• MODE: To define the instrument’s response to Voice messages, Mode messages are sent over an instrument’s Basic Channel.
4.3.3 System messages
System messages are not encoded with channel numbers. There are three types of System messages:
Common, Real-Time, and Exclusive.
• COMMON: Common messages are intended for all receivers In a system regardless of channel.
• REAL-TIME: Real-Time messages are used for synchronization and are intended for all clock- based instruments in a system. They contain Status bytes only — no Data bytes. Real-Time messages may be sent at any time — even between bytes of a message which has a different status. In such cases the Real-Time message is either acted upon or ignored, after which the receiving process resumes under the previous status.
• EXCLUSIVE: Exclusive messages can contain any number of Data bytes, and can be terminated either by an End of Exclusive (EOX) or any other Status byte (except Real Time messages). An EOX should always be sent at the end of a System Exclusive message. These messages include a Manufacturer’s Identification (ID) code. If a receiver does not recognize the ID code, it should ignore the following data.
So that other users and third party developers can fully access their instruments, manufacturers shall publish the format of the System Exclusive data following their ID code. Only the manufacturer can define or update the format following their ID.
4.4 Data types
4.4.1 General
There are two types of bytes sent over MID I: Status Bytes and Data bytes.
4.4.2 Status bytes General
Status bytes are eight-bit binary numbers in which the Most Significant Bit (MSB) is set jbinary ).
Status bytes serve to identify the message type, that is, the purpose of the Data bytes which follow it.
Except for Real-Time messages, new Status bytes will always command a receiver to adopt a new
status, even if the last message was not completed. Running status
For Voice and Mode messages only. When a Status byte is received and processed, the receiver will remain in that status until a different Status byte is received. Therefore, if the same Status byte would be repeated, it can optionally be omitted so that only the Data bytes need to be sent. Thus, with Running Status, a complete message can consist of only Data bytes.
Running Status is especially helpful when sending long strings of Note OnlOff messages, where “Note On with Velocity of 0” is used for Note Off.
Running Status will be stopped when any other Status byte intervenes. Real-Time messages should not affect Running Status. UnImplemented status
Any status bytes, and subsequent data bytes, received for functions not implemented in a receiver should be ignored. Undefined status
All MIDI instruments should be careful to never send any undefined status bytes. If an instrument receives any such code, it should be ignored without causing any problems to the system. Care should also be taken during power-up and power-down that no messages be sent out the MIDI Out port. Such noise, if it appears on a MIDI line, could cause a data or framing error if the number of bits in the byte is incorrect.DIN EN 63035 pdf download.