The value of this field specifies the size of the parameter value stored in the data field. Data length
indicates the length of the array being transferred minus 1 when the parameter contains a character
string or other similar array structure.
15.3.13 data : Parameter Data
Format: index0 0dddddddB (0eeeeeeeB) (0fffffffB) (0gggggggB) (0hhhhhhhB)
index1 0dddddddB (0eeeeeeeB) (0fffffffB) (0gggggggB) (0hhhhhhhB)
index2 0dddddddB (0eeeeeeeB) (0fffffffB) (0gggggggB) (0hhhhhhhB)
: :
indexN 0dddddddB (0eeeeeeeB) (0fffffffB) (0gggggggB) (0hhhhhhhB)
Parameter data indicates the parameter value. The data array size is len + 1. For a one data item
structure, the length depends on the data bit width, as shown below.
dddddB + 1 Number of data
1 - 7 1
8 - 14 2
15 - 21 3
22 - 28 4
29 - 32 5
Each block of data is packed from the lowest order byte first. In the case of multiple-byte data, the
lowest weighted bit is the LSB of the first data block, and the highest weighted bit is the MSB of
the final data block. The following shows an example of how data would be divided for transfer in
the case of 32-bit data.
7 6 5 4 3 2 1 0
data0: 0 [bit06] [bit05] [bit04] [bit03] [bit02] [bit01] [bit00]
data1: 0 [bit13] [bit12] [bit11] [bit10] [bit09] [bit08] [bit07]
data2: 0 [bit20] [bit19] [bit18] [bit17] [bit16] [bit15] [bit14]
data3: 0 [bit27] [bit26] [bit25] [bit24] [bit23] [bit22] [bit21]
data4: 0 0 0 0 [bit31] [bit30] [bit29] [bit28]
Single Message Size Limit
With the Instruments system exclusive message format, the size of a single message cannot exceed 48
bytes. The data size and the array size, however, can cause a packet to exceed 48 bytes when transferring
a single parameter array. In this case, the IPS and IPR message data length and data index number
values can be modified to enable division of a single parameter value into multiple messages so it can be
sent that way.
15.3.14 EOX : End of System Exclusive Message
Format: 11110111B
This is the End of System Exclusive Message status byte established by the MIDI standard.
16 Parameter Transfer
There are two parameter operations: Individual Parameter Transfer and Individual Parameter Request.
34
To Next Page
Loading...
Need help?
General
