Assessments - 3, GPA: 4.7
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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. ♦ The number of bytes comprising address data varies from one model ID to another,. ♦ The error checking process uses a checksum that provides a bit pattern where lower seven bits are zero when values for an address, size, and that checksum are summed. # Acknowledge ; ACK (43H) This message is sent out when no error was detected on reception of a WSD, DAT, "End of data (EOD)”, or some other message and a requested setup or action is complete. Unless it receives an ACK message, the device at the other end will not proceed to the next operation. Byte Description FOH Exclusive status 4 1 H Manufactures ID (Roland) DEV Device ID MDL Model ID 43H Command ID F7H End of exclusive # End of data ; EOD (45H) This message is sent out to inform a remote device of the end of a message. Communication, however, will not come to an end unless the remote device returns an ACK message even though an EOD message was transmitted. Byte Description FOH Exclusive status 4 1 H Manufactures ID (Roland) DEV Device ID MDL Model ID 45H Command ID F7H End of exclusive # Communications error : ERR (4EH) This message warns the remote device of a communications fault encountered during message transmission due, for example, to a checksum error. An ERR message may be replaced with a "Rejection (RJC)” one, which terminates the current message transaction in midstream. When it receives an ERR message, the sending device may either attempt to send out the last message a second time or terminate communication by sending out an RJC message. Byte Description FOH Exclusive status 4 1 H Manufactures ID (Roland) DEV Device ID MDL Model ID 4EH Command ID F7H End of exclusive 5 # Rejection ; RJC (4FH) This message is sent out when there is a need to terminate communication by overriding the current message. An RJC message will be triggered when : a WSD or RQD message has specified an illegal data address or size, or the device is not ready for communication. an illegal number of addresses or data has been detected. data transfer has been terminated by an operator. a communications error has occurred. An ERR message may be sent out by a device on either side of the interface . Communication must be terminated immediately when cither side triggers an ERR message. Byte Description FOH Exclusive status 41 H Manufactures ID (Roland) DEV Device ID MDL Model ID 4FH Command ID F7H End of exclusive # Example of Message Transactions + Data transfer from device (A) to device (B). Device (A) [Want to send data] [Data set] - [Data set] - [End of data] | Device (B) | [Acknowledge] [Acknowledge] [Acknowledge] [Acknowledge] • Error occurs while device (A) is receiving data from device (B). 1) Data transfer from device (A) to device (B). I Device (A) j [Acknowledge] - (Error) x [Communication error] [Acknowledge] - j Device (B) j — [Data set] — [Data set] — [Data set] (the same data — as above) 2) Device (B) rejects the data re - transmitied, and completes data transfer. Device (A) [Acknowledge] - (Error) x -«a— [Communication error]-(Complete) — j Device (B) j [Data set] [Data set] [Rejection] 3) Device (A) immediately completes data transfer. Device (A) [Acknowledge] (Error) x [Rejection] Device (B) [Data set] [Data set] (Complete) # Device (A) requests and receives data from device (B). Device (A) [Request data] [Acknowledge] [Acknowledge] [Acknowledge] j Device (B) | [Data set] [Data set] [End of data] 6 Roland Harpsichord Classic 50/20 MIDI Implementation Jan.15 1988 Version 1.00 TRANSMITTED DATA e Harpsichord has been appled while the TRANSPOSE/MIDI h is held down: ing a tone selector switch calls the tone just the same the normal tone changing. At the same time the Program e assigned to the tone is sent. Status 9nH Note on Status 9nH Second kkH kk = Note number n = MIDI Channel Second kkH = Velocity of note numbe 17H -OH - Third 00H 5EH FH ( 23 - 94 ) ( 1 - 16 ) ¡hanged by transpos of the transpositi The range of note numbers can be c The table below lists the degrees The default value is 0. To transpose the keyboard, hold down the TRANSPOSE/MIDI then press the (b] switch to key down or [#] to key up, for on semitone. Pressing the [ b ] switch more than fi timca ( I #1,5 times not introduce further effect. To return the keyboard back to the original notes, press ) docs the [ . Tra spos alu itted note range LUTE STRINGS ORGAN- I ORGAN- II 8’ - I LUTE When the Harp STRING STRINGS STRINGS STRINGS STRINGS ORGAN- I ORGAN- I ORGAN- 1 ORGAN- 1 ORGAN- I ORGAN- 11 ORGAN- 11 ORGAN- il ORGAN- 11 ORGAN-И n MULTI TIMBRE MODE, different prograi ntioned is sent when tone is changed. ( MULTI TIMBRE MODE ) I Control change Ho 1 -1 tatus Secon BnH 4 OH Status Second Third BnH 0BH vvH vv = Exp...