CanServo/Protocol/V1.1

CAN Protocol Ver 1.1

• This protocol needs FW Ver 1.12+

• Through this message, you can control the servo based on the UID of the servo.
• Even if the ID1 and ID2 of the servo are 0, the register value of the servo can be changed.

• CAN ID
  • 0x7FF : Servo -> Host
  • 0x7FE : Host -> Servo

• Message : Servo -> Host
  • ZUID, <UID : 16 byte>, <ID2 : 4 byte>, <ID1 : 1 byte>, <CAN Mode : 1 byte>

• Message: Host -> Servo
  • ZIDS, <UID : 16 byte>, <ID2 : 4 byte>
  • ZIDS, <UID : 16 byte>, <ID2 : 4 byte>, <ID1 : 1 byte>
  • ZIDS, <UID : 16 byte>, <ID2 : 4 byte>, <ID1 : 1 byte>, <CAN Mode : 1 byte>

• This message is delivered using the MultiPacket method below.

MultiPacket for Long Message

• Since this message is over 8 bytes in length, it is divided into multiple packets and delivered.
  • Since the maximum data length of a CAN 2.0 packet is 8 bytes, 7 bytes are cut from the entire message, and information such as order is delivered as the last byte.
  • To verify Message delivery error, a 2-byte value calculated by CRC16 is added, and 7 bytes are cut and sent.

• Multi Packet's Data Format
  • < Data : max 7 byte, cut from 'Message + CRC16' >, <Check Byte>
  • Check Byte
    • bit 7 = 1, if first packet
    • bit 6 = 1, if last packet
    • bit 5 = Toggle, first packet = 1, toggle bit on each packet
    • bit 4:0 = Seq, 0 ~ 31, inc 1 on each message

• Note:
  • ID2, CRC16 : byte order : low byte first, little endian

• Reference:
  • Code/CRC16