DPC-CAN/PROTOCOL/ENG

What is DPC-CAN ?

• DPC-CAN is setup and test Interface for HiTEC RCD CAN Servo.
• Serial Communication via CP2xxx
• CAN 2.0B Interface
  • CAN 2.0A message, 2.0B message
• USB connector.
• 3 pin power connector.
  • GND, POWER+, NC
• 4 pin CAN connector.
  • GND, POWER+, CANL, CANH

• You can use CANL, CANH without GND, POWER+.
  • We recommand use GND with CANL/H.

Packet

<Start Flag>, <Msg: n byte>, <Add Checksum of Msg>, <MsgLen = n>, <End Flag>

• You must use packet form to send Msg or parsing Msg.
  • Except FIXED FORMAT.
  • ex) Write n bytes: xxxxx

• Host -> DPC-CAN
  • Start Flag = STX = 2, End Flag = ETX = 3

• DPC-CAN -> Host
  • if CAN Recv Msg, Start Flag = STX+2 = 4, End Flag = ETX+2 = 5
  • if Error Msg, Start Flag = STX+4 = 6, End Flag = ETX+4 = 7

Connect

• Connect DPC-CAN to PC.
• Open Serial Port
  • 115200 bps, 8, n, 1
• Write: 6 bytes: ':', 'A', ':', 'A', ':', 'A'
• Wait 500 msec
• Write: 4 bytes: 2, 'X', 'X', 3
• Wait 100 msec
• Clear recv buffer
• Write: 8 bytes: 2, 'V', 'S', 0, 0, 0, 0, 3
• Wait 500 msec
• Read all recv bytes
  • Find Value 4
  • get next 2 bytes
  • format = 4, <VER H>, <VER L>
• Check Version of DPC-CAN
• Init DPC-CAN
• Now You can send or recv CAN 2.0A, 2.0B messages.

• Connect Servo to DPC-CAN
• Power On Servo

Version

• VER H
  • bit 7..4:
    • 0 or 1 = Bootloader Type 1 = B1
    • 2 = Bootloader Type 2 = B2
  • bit 3..0:
    • 0 or 1 = DPC-CAN FW V1
    • 2 = DPC-CAN FW V2
• VER L
  • Firmware Version
  • ex) 23 -> Ver 2.3

• YOU MUST CHECK DPC-CAN FW V2, Ver 2.2+

Disconnect

• Close Serial Port

Init

'S' - set baudrate, sample point

'S', <speed index>, <sampling point index>

• ex) 'S', 0, 0 --> 1000 kbps, 50%
• speed table
  • 0 = 1000
  • 1 = 800
  • 2 = 750
  • 3 = 500
  • 4 = 400
  • 5 = 250
  • 6 = 200
  • 7 = 150
  • 8 = 125
• sampling point
  • 0 = 50%
  • 1 = 87.5% (recommanded)

'T' - set default target can id

'T', <CAN ID byte 0>, <CAN ID byte 1>, <CAN ID byte 2>, <CAN ID byte 3>

• You can send 'M' Msg, after this setting.
• CAN ID
  • little endian
  • if CAN ID byte 3, bit 7 is 1, this is 2.0B CAN ID.

'?' - get configuration

• You can get CAN baudrate and DEFAULT TARGET CAN ID.

• SEND
  • Write 3 bytes: 2, '?', 3 --> THIS IS NOT PACKET FORM
• RETURN

'U', <can speed index>, <can sample point index>, <ID byte 0>, <ID byte 1>, <ID byte 2>, <ID byte 3>

send can message

• You must use packet form
  • Start Flag = STX, End Flag = ETX

'M' - send CAN message with default target can id

'M', < data byte 0 >, ..., < data byte n-1 >

• Msg length is 1 ~ 9 bytes.
• ex) send CAN 2.0A message "HELLO" with default can id
  • 'M', 'H', 'E', 'L', 'L', 'O'

'A', 'C' - send CAN 2.0A message

'A', <CAN ID byte 0>, <CAN ID byte 1>, <data byte 0>, ..., <data byte n-1>

• Msg length is 3 ~ 11 bytes.
• ex) send CAN 2.0A message "HELLO" with CAN ID 0x123
  • 'A', 0x23, 0x01, 'H', 'E', 'L', 'L', 'O'

• if you use 'C' instead of 'A', default target can id will be changed.

'B', 'D' - send CAN 2.0B message

'B', <CAN ID byte 0>, <CAN ID byte 1>, <CAN ID byte 2>, <CAN ID byte 3>, <data byte 0>, ..., <data byte n-1>

• Msg length is 5 ~ 13 bytes.
• ex) send CAN 2.0B message "HELLO" with CAN ID 0x12345678
  • 'B', 0x78, 0x56, 0x34, 0x12, 'H', 'E', 'L', 'L', 'O'

• if you use 'D' instead of 'B', default target can id will be changed.

read messages

• if DPC-CAN recv normal CAN message from CAN network, DPC-CAN send CAN Data in packet form to PC.
  • Start Flag = STX+2 = 4, End Flag = ETX+2 = 5
• if DPC-CAN detect error, DPC-DPC send error Msg in packet form to PC.
  • Start Flag = STX+4 = 6, End Flag = ETX+4 = 7

error messages

• "SET" message
  • You need setup baudrate and sample point to send any packet.

• "ID" message
  • You need setup default target can id to send 'M' Msg.

recv CAN message

• only One format

<CAN ID byte 0>, <CAN ID byte 1>, <CAN ID byte 2>, <CAN ID byte 3>, <data byte 0>, ..., <data byte n-1>

• Msg Length is 4 ~ 12 bytes.
• CAN ID is 4 byte fixed.
• if CAN ID byte 3 bit 7 is 1, this is CAN 2.0B message.

• ex) 0x78, 0x56, 0x34, 0x92, 0x99
  • CAN 2.0B Message, ID = 0x12345678, Data Len = 1, Data = 0x99