User manual ROLAND GT-3 V1.00 MIDI IMPLEMENTATION

[. . . ] * There are four Program Change Maps which are referenced when selecting programs, and these are switched by Bank Select messages. * For more details, please refer to "Roland Exclusive Message". 3. EXCLUSICE COMMUNICATION On the GT-3, exclusive messages can be used as follows. [. . . ] It sends out an Exclusive message completely independent of the receiving device's status. Manufacturer ID: 41H The Manufacturer ID identifies the manufacturer of a MIDI instrument that sends an Exclusive message. Value 41H represents Roland's Manufacturer ID. Connection Diagram Device (A) MIDI OUT MIDI IN 1 2 Device (B) MIDI IN MIDI OUT Device ID: DEV The Device ID contains a unique value that identifies individual devices in the implementation of several MIDI instruments. It is usually set to 00H-0FH, a value smaller by one than that of a basic channel, but value 00H-1FH may be used for a device with several basic channels. Connection at point 2 is essential for "Request data" procedures. (See Section 3. ) Model ID: MDL The Model ID contains a value that identifies one model from another. Different models, however, may share an identical Model ID if they handle similar data. The Model ID format may contain 00H in one or more places to provide an extended data field. The following are examples of valid Model IDs, each representing a unique model: 01H 02H 03H 00H, 01H 00H, 02H 00H, 00H, 01H Handshake-transfer procedure (This device does not use this procedure) This procedure initiates a predetermined transfer sequence (handshaking) across the interface before data transfer takes place. Handshaking ensures that reliability and transfer speed are high enough to handle a large amount of data. Connection Diagram Device (A) MIDI OUT MIDI IN 1 2 Device (B) MIDI IN MIDI OUT Connection at points 1 and 2 is essential. Command ID: CMD The Command ID indicates the function of an Exclusive message. The Command ID format may contain 00H in one or more places to provide an extended data field. The following are examples of valid Command IDs, each representing a unique function: Notes on the above procedures * There are separate Command IDs for different transfer procedures. * Devices A and B cannot exchange data unless they use the same transfer procedure, share identical Device ID and Model ID, and are ready for communication. 01H 02H 03H 00H, 01H 00H, 02H 00H, 00H, 01H 21 GT-3 MIDI Implementation 3. One-way Transfer Procedure This procedure sends out data until it has all been sent and is used when the messages are so short that answerbacks need not be checked. For longer messages, however, the receiving device must acquire each message in time with the transfer sequence, which inserts 20 milliseconds intervals. Types of Messages Message Request data 1 Data set 1 Command ID RQ1 (11H) DT1 (12H) more bits of data as well as a series of data formatted in an address-dependent order. The MIDI standards inhibit non real-time messages from interrupting an Exclusive one. [. . . ] * The same number of bytes comprises address and size data, which, however, vary with the Model ID. * The error-checking process uses a checksum that provides a bit pattern where the last 7 bits are zero when values for an address, size, and that checksum are summed. [Data set 1] * More than 20 msec time internal. [. . . ]