User manual ROLAND GT-5 V1.00 MIDI IMPLEMENTATION

[. . . ] While message intervals are being monitored, an interval greater than 400 msec between messages will cause the system parameter "Assign Hold" to be turned "Off" (if it is already "On") from the next Patch change. At this time message interval monitoring will also be halted. Status FAH Stop Status FCH Copyright © 1997 BOSS CORPORATION All rights reserved. [. . . ] Address-mapped Data Transfer Address mapping is a technique for transferring messages conforming to the data format given in Section 1. It assigns a series of memoryresident records--waveform and tone data, switch status, and parameters, for example, to specific locations in a machine-dependent address space, thereby allowing access to data residing at the address a message specifies. Address-mapped data transfer is therefore independent of models and data categories. This technique allows use of two different transfer procedures: one-way transfer and handshake transfer. ·MIDI status: F0H, F7H An Exclusive message must be flanked by a pair of status codes, starting with a Manufacturer ID immediately after F0H (MIDI version 1. 0). ·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. ·One-way transfer procedure (See Section 3 for details. ) This procedure is suited to the transfer of a small amount of data. It sends out an Exclusive message completely independent of the receiving device's status. Connection Diagram ·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 00H­0FH, a value smaller by one than that of a basic channel, but value 00H­1FH may be used for a device with several basic channels. Device (A) MIDI OUT MIDI IN 1 2 Device (B) MIDI IN MIDI OUT 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. Notes on the above procedures ·Command ID: CMD The Command ID indicates the function of an Exclusive message. [. . . ] * The error-checking process uses a checksum that provides a bit pattern where the last 7 bits are zero when values for an address, data, and that checksum are summed. ·Example of Message Transactions * The size of the requested data does not indicate the number of bytes that will make up a DT1 message, but represents the address fields where the requested data resides. * Some models are subject to limitations in data format used for a single transaction. Requested data, for example, may have a limit in length or must be divided into predetermined address fields before it is exchanged across the interface. [. . . ]