Long Packet - FUTABA RS301CR Instruction Manual

This notation indicates an address on the memory map. Using this address makes it possible
Address
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
Length = the number of bytes of data
This notation indicates the number of servos, which should be set at "1" for a short packet.
Count
This notation indicates the data to be stored in the memory map.
Data
This is the check sum of a packet using 8 bits. Check sum is the value obtained from XOR
Sum
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
FA AF 01 00
The check sum of the transmission data above is as follows:
01H 00H
XOR XOR
●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
Header ID Flags Address Length Count
Header
This notation indicates the front of a packet. Set "FAAFH" for long packets.
"xH" denotes Hexadecimal number.
ID
This should be always kept at 00H.
Flags
This should be always kept at 00H.
1E 02 01 00 00
1EH 02H
XOR XOR
Sum
1C
01H 00H
XOR XOR
Length
VID Data VID
Number of servos = Count
14
00H
Data VID Data Sum