Roland XV-5080 owner manual 303, Example of an Exclusive message and calculating a checksum

during the song and then rewound or fast-forwarded, the sequencer may not be able to transmit the correct status, and the sound generator will then misinterpret the data. Take care to give each event its own status.

It is also necessary that the RPN or NRPN parameter number setting and the value setting be done in the proper order. On some sequencers, events occurring in the same (or consecutive) clock may be transmitted in an order different than the order in which they were received. For this reason it is a good idea to slightly skew the time of each event (about 1 tick for TPQN = 96, and about 5 ticks for TPQN = 480).

*TPQN: Ticks Per Quarter Note

●Example of an Exclusive message and calculating a checksum

Roland Exclusive messages (RQ1, DT1) are transmitted with a checksum at the end (before F7) to make sure that the message was correctly received. The value of the checksum is determined by the address and data (or size) of the transmitted Exclusive message.

❍How to calculate the checksum (hexadecimal numbers are indicated by

"H")

The checksum is a value derived by adding the address, size, and checksum itself and inverting the lower 7 bits.

Here's an example of how the checksum is calculated. We will assume that in the Exclusive message we are transmitting, the address is aa bb cc ddH and the data or size is ee ffH.

aa+ bb + cc + dd + ee + ff = sum sum ÷ 128 = quotient ... remainder 128 - remainder = checksum

<Example 1> Setting CHORUS TYPE of PERFORMANCE COMMON to DELAY (DT1).

According to the "Parameter Address Map (p. 290)", the start address of Temporary Performance is 10 00 00 00H, the offset address of CHORUS at PERFORMANCE COMMON is 04 00H, and the address of CHORUS TYPE is 00 00H. Therefore the address of CHORUS TYPE of PERFORMANCE COMMON is;

	10	00 00	00H
		04	00H
+)		00	00H
	10	00 04	00H
DELAY has the value of 02H.
So the system exclusive message should be sent is;
F0	41	10	00 10	12	10 00 04 00	02	??	F7
(1)	(2)	(3)	(4)	(5)	address	data	checksum	(6)
(1) Exclusive Status,				(2) ID (Roland),		(3) Device ID (17),
(4) Model ID (XV-5080),				(5) Command ID (DT1),		(6) End of Exclusive

Then calculate the checksum.

10H + 00H + 04H + 00H + 02H = 16 + 0 + 4 + 0 + 2 = 22 (sum) 22 (sum) ÷ 128 = 0 (quotient) ... 22 (remainder)

checksum = 128 - 22 (remainder) = 106 = 6AH

This means that F0 41 10 00 10 12 10 00 04 00 02 6A F7 is the message should be sent.

<Example 2> Getting the data (RQ1) of Performance Part 3 in USER:03.

According to the "Parameter Address Map (p. 290)", the start address of USER:03 is 20 02 00 00H, and the offset address of Performance Part 3 is 00 22 00H.

Therefore the start address of Performance Part 3 in USER:03 is;

20 02 00 00H +) 00 22 00H 20 02 22 00H

As the size of Performance Part is 00 00 00 21H, the system exclusive message should be sent is;

F0	41	10	00 10	11	20 02 22 00	00 00 00 21	??	F7
(1)	(2)	(3)	(4)	(5)	address	data	checksum	(6)

MIDI Implementation

(1) Exclusive Status,	(2) ID (Roland),	(3) Device ID (17),
(4) Model ID (XV-5080),	(5) Command ID(RQ1),	(6) End of Exclusive

Then calculate the checksum.

20H + 02H + 22H + 00H + 00H + 00H + 00H + 21H = 32 + 2 + 34 + 0 + 0 + 0 + 0 + 33 = 101 (sum)

101 (sum) ÷ 128 = 0 (quotient) ... 101 (remainder) checksum = 128 - 101 (remainder) = 27 = 1BH

This means that F0 41 10 00 10 11 20 02 22 00 00 00 00 21 1B F7 is the message should be sent.

<Example 3> Getting Temporary Performance data (RQ1);

cf.) This operation is the same as Data Transfer function in Utility mode with "PERFORM" (Type parameter) and "TEMP: -PATCH" (Source parameter) options.

According to the "Parameter Address Map (p. 290)", the start address of Temporary Performance is assinged as following:

10 00 00 00H Temporary Performance Common

:

10 00 20 00H Temporary Performance Part 1

:

10 00 3F 00H Temporary Performance Part 32

As the data size of Performance Part is 00 00 00 21H, summation of the size and the start address of Part 32 at Temporay Performance will be;

10 00 3F 00H

+) 00 00 00 21H

10 00 3F 21H

And the size that have to be got should be;

10 00 3F 21H

-) 10 00 00 00H

00 00 3F 21H

Therefore the system exclusive message should be sent is;

F0	41	10	00 10	11	10 00 00	00	00 00 3F 21	??	F7
(1)	(2)	(3)	(4)	(5)	address		data	checksum	(6)
(1) Exclusive Status,				(2) ID (Roland),			(3) Device ID (17),
(4) Model ID (XV-5080),				(5) Command ID (RQ1),			(6) End of Exclusive

Calculating the checksum as shown in <Example 2>, we get a message of F0 41 10 00 10 11 10 00 00 00 00 00 3F 21 10 F7 to be transmitted.

<Example 4> Getting data (RQ1) at once; Tempory Performance data,

Temporary Patch data of whole part in Performance mode,

Temporary Rhythm data of whole part in Performance mode.

cf.) This operation is the same as Data Transfer function in Utility mode with "PERFORM" (Type parameter) and "TEMP: +PATCH" (Source parameter) options.

According to the "Parameter Address Map (p. 290)", the start address of the above all parameters is assinged as following:

10 00 00 00H Temporary Performance

11 20 00 00H Temporary Patch (Performance Mode Part 1)

11 30 00 00H Temporary Rhythm (Performance Mode Part 1)

:

14 60 00 00H Temporary Patch (Performance Mode Part 16)

14 70 00 00H Temporary Rhythm (Performance Mode Part 16)

The offset address of Rhythm is also assigned as follows:

00	00 00H	Rhythm Common
	:
00	10 00H	Rhythm Tone 1
	:
01	3E 00H	Rhythm Tone 4

Appendices

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