Index Parameter Index Number - Casio CTK-900 Midi Implementation Manual

17.2.10

10...index Parameter Index Number

When act = 00(IPC) or 01(IPR)
Format: 0iiiiiiiB
This field contains a supplementary number that points to data when parameters are arrayed. This means that each
parameter has a different number, and the length of the number is anywhere from one to four bytes.
Even when parameters have the same IDs, for example, the parameters also have preset numbers, part numbers,
and key numbers, and so the parameters can be distinguished by specifying these values with an "index".
When act = 02(BDS) or 04(HDS)
Format: 0nnnnnnnB
In this case, "index" is a 3-byte fixed field. When transferring one parameter set, it indicates the divided packet
serial number (starting with 00) and the size of the "data" field that immediately follows this field.
i[0]...0nnnnnnnB Packet Number LSB (NNNNNNNnnnnnnnB = Packet Number)
i[1]...0NNNNNNNB Packet Number MSB
As detailed in the "data" field explanation, up to 128 bytes of data can be send in one packet. When sending data
in excess of 128 bytes, it is divided into 128-byte packets (final packet can be less than 128 bytes), and received
data is stored at the address equivalent to:
i[2]...0LLLLLLLB data length / 3
The data length is the data length indicated here, multiplied by 3. This means that the data length is always a
multiple of 3.
When act = 03(BDR) or 05(HDR)
Format: -
This field is always empty.
When act = 7 (EOD, HDA, HDJ, HDE, BSY, EOS, NOP)
Format: 0000ccccB
In this case, the "index" field length is fixed at 1 byte, and it indicates the control messages used for handshaking
as shown below. See "19 Parameter Set Transfer Protocols" for more information.
(0jjjjjjjB) (0kkkkkkkB)
0NNNNNNNB 0LLLLLLLB
ParameterSet Start Address + PacketNumber × 128
35
(0lllllllB)