User manual - PX150_1200_AP250_650_midi

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 Instrument’s 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.
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