Casio WK3800 Instruction Manual - Page 36

17.2.10 10...index Parameter Index Number When act = 00(IPC) or 01(IPR) Format: 0iiiiiiiB (0jjjjjjjB) (0kkkkkkkB) (0lllllllB) 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 0NNNNNNNB 0LLLLLLLB 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: ParameterSet Start Address + PacketNumber × 128 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. 36