Futaba RS302CD - Manual (Page 14)

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This notation indicates an address on the memory map. Using this address makes it possible
to write the data of the specified number of bytes determined by the “Length” into the
memory map.
This notation indicates the length of a data block.
Length = the number of bytes of data
This notation indicates the number of servos, which should be set at “1” for a short packet.
This notation indicates the data to be stored in the memory map.
This is the check sum of a packet using 8 bits. Check sum is the value obtained from XOR
operation on all bytes from ID through Data in a packet by a unit of a byte.
If the number of bytes from ID through Data in a packet is two or larger, divide them
byte-by-byte and conduct XOR operation on them.
Ex) Send a command ordering ID1 servo to move to 0 degree.
Hdr ID Flg Adr Len Cnt Dat Sum
The check sum of the transmission data above is as follows:
01H
XOR 00H XOR 1EH XOR 02H XOR 01H XOR 00H XOR 00H
● Long Packet
The long packet is used to send the data in the memory map to multiple servos. Please
note, however, that the memory address and the length of the data to be sent are the same
to all the servos.
Packet structure
This notation indicates the front of a packet. Set “FAAFH” for long packets.
“xH” denotes Hexadecimal number.
This should be always kept at 00H.
This should be always kept at 00H.
Address
Length
Count
Data
Sum
FA AF 01 00 1E 02 1C 00 00 01
Header ID Flags Address Length Count Data Sum
Header
ID
Flags
VID Data VID Data VID
Number of servos = Count
Length