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Introduction

DYNAMIXEL servos utilize the DYNAMIXEL protocol for serial communications and control operations. This document serves as a reference for the specifications of 2.0 DYNAMIXEL Protocol communication.

DYNAMIXEL Protocol 2.0 communications are supported on the following servos:

note

Note: MX(2.0) is a special firmware for the DYNAMIXEL MX series providing support for DYNAMIXEL Protocol 2.0. MX(2.0) firmware can be uploaded to your servo using Firmware Recovery in DYNAMIXEL Wizard 2.0.

DYNAMIXEL Protocol 2.0 communications are supported by the following controllers:

tip

TIP : See the DYNAMIXEL Protocol Compatibility Table for more information.

Packet​

DYNAMIXELs communicate with their controllers using structured data packets in one of two types:

  1. Instruction Packets: Sent by the main controller to the DYNAMIXEL. These packets contain the instructions for the actuators.
  2. Status Packets: Sent by the DYNAMIXEL back to the main controller. These packets return information reported by the actuator.

ID​

Each DYNAMIXEL servo is assigned a communication ID for identification over the DYNAMIXEL bus.

Each connected DYNAMIXEL must have a unique ID number. If DYNAMIXELs with the same ID are connected, packet collision and network problems will occur. To change a DYNAMIXEL's ID, reference the DYNAMIXEL Control Table section on the DYNAMIXEL Wizard 2.0 eManual page.

note

NOTE: The default ID number for new DYNAMIXEL actuators is 1.

DYNAMIXEL Protocol​

DYNAMIXEL servos utilize half-duplex 8 bit Asynchronous Serial Communication with 1 Stop bit, and no Parity.

Half Duplex​

Half duplex UART is a serial communication protocol where both TxD and RxD cannot be used at the same time. This method is generally used when many devices need to be connected to a single bus. Since multiple devices are connected to the same bus, all the other devices need to be in input mode while one device is transmitting. The Main Controller that controls DYNAMIXEL actuators also controls the switch between input and output communications modes.

Tx, Rx Direction​

For Half Duplex UART, the transmission ending timing is important to change the direction between sending and receiving mode. The bit definitions within the UART_STATUS register are as follows:

  • TXD_BUFFER_READY_BIT: Indicates that the transmission DATA can be loaded into the Buffer. Note that this only means that the SERIAL TX BUFFER is empty, and does not necessarily mean that the all the data transmitted before has left the CPU.
  • TXD_SHIFT_REGISTER_EMPTY_BIT: Set when all the Transmission Data has completed its transmission and left the CPU.

The TXD_BUFFER_READY_BIT is used when one byte is to be transmitted via the serial communication channel, and an example is shown below.

TxDByte(byte bData)
{
  while(!TXD_BUFFER_READY_BIT); //wait until data can be loaded.
  SerialTxDBuffer = bData; //data load to TxD buffer
}

Before changing the communication direction, the TXD_SHIFT_REGISTER_EMPTY_BIT must be checked to ensure that all data has been transferred. The following is an example program that sends an Instruction Packet and waits until communciation has been completed before switching communication directions.

1  DIRECTION_PORT = TX_DIRECTION;
2  TxDByte(0xff);
3  TxDByte(0xff);
4  TxDByte(0xfd);
5  TxDByte(0x00);
6  TxDByte(bID);
7  TxDByte(bLengthLow);
8  TxDByte(bLengthHigh);
9  TxDByte(bInstruction);
10  TxDByte(Parameter0); TxDByte(Parameter1); ...
11  TxDByte(bCrcLow);
12  DisableInterrupt(); // interrupt should be disable
13  TxDByte(bCrcHigh);  // last TxD
14  while(!TXD_SHIFT_REGISTER_EMPTY_BIT); // Wait till last data bit has been sent
15  DIRECTION_PORT = RX_DIRECTION; // Direction change to RXD
16  EnableInterrupt(); // enable interrupt again
warning

WARNING : Please note the lines between LINE 12 and LINE 16. Line 12 is necessary since an interrupt during data transmission may cause a delay longer than the return delay time and corruption to the status packet may occur.

Byte to Byte Time​

The allowed delay time between bytes when sending an instruction packet is 1.5ms. If the delay time is over 1.5ms, then DYNAMIXEL actuator recognizes this as a communication problem and waits for the next header (0xff 0xff 0xfd) before continuing to process packets.

Instruction Packet

Instruction Packet is the command packet sent to provide instructions to the Device. The structure of the packet is as follows:

Header 1Header 2Header 3ReservedPacket IDLength 1Length 2InstructionParamParamParamCRC 1CRC 2
0xFF0xFF0xFD0x00IDLen_LLen_HInstructionParam 1...Param NCRC_LCRC_H

This field is used to indicate the start of a status packet.

Reserved​

An additional 0x00 byte included in the header field.

Example DYNAMIXEL packet

Packet ID​

The field that indicates the ID of the device that should receive the Instruction Packet and process it.

  1. Range : 0 ~ 252 (0x00 ~ 0xFC), which is a total of 253 numbers that can be used.
  2. Broadcast ID : 254 (0xFE), which makes all connected devices execute the Instruction Packet.
warning

WARNING: The DYNAMIXEL Broadcast ID (254 (0xFE)) will only return Status Packets for Ping, Sync Read and Bulk Read commands, other Instructions aside from Ping, Sync Read and Bulk Read will not return Status Packets when sent to the Broadcast ID.

Length​

The field that specifies the full length of the transmitted packet, Divided into low and high bytes in the Instruction Packet. The Length includes the Byte size of Instruction, Parameters and CRC fields in the packet.

  • Length = the number of Parameters + 3
  • A returned Status Packet will also include a 1 byte length ERROR field in the data.

Instruction​

The field that defines the type of command included in the instruction packet.

ValueInstructionsDescription
0x01PingInstruction that checks whether the Packet has arrived at a device with the same ID as the specified packet ID
0x02ReadInstruction to read data from the Device
0x03WriteInstruction to write data to the Device
0x04Reg WriteInstruction to register the Instruction Packet in standby status; Packet can later be executed using the Action command
0x05ActionInstruction to executes a Packet that was registered beforehand using Reg Write
0x06Factory ResetInstruction that resets the Control Table to its initial factory default settings
0x08RebootInstruction to reboot the Device
0x10ClearInstruction to reset certain information stored in memory
0x20Control Table BackupInstruction to store current Control Table status data to a Backup or to restore backup EEPROM data.
0x55Status(Return)Return packet sent following the execution of an Instruction Packet
0x82Sync ReadInstruction to read data from multiple devices with the same Address with the same length at once
0x83Sync WriteInstruction to write data to multiple devices with the same Address with the same length at once
0x8AFast Sync ReadInstruction to read data from multiple devices with the same Address with the same length at once
0x92Bulk ReadInstruction to read data from multiple devices with different Addresses with different lengths at once
0x93Bulk WriteInstruction to write data to multiple devices with different Addresses with different lengths at once
0x9AFast Bulk ReadInstruction to read data from multiple devices with different Addresses with different lengths at once

Parameters​

This section contains the data sent in the packet, and may differ in length and content depending on the type of packet sent.

warning

WARNING: The method of expressing negative numbers in this data field may differ for each product. Please refer to the eManual page for your specific product for more information.

CRC​

A 16bit checksum used to determine if the Packet has been damaged during communication. This field is divided into low and high bytes in the Instruction Packet and is calculated based on the content of the packet ranging from the Header (FF FF FD 00) to to the Parameters before the CRC field in the Instruction Packet. See the following page for CRC Calculation documentation.

Status Packet

The Status Packet is the response transmitted from the device to the main controller following the receipt of an Instruction Packet. Note that it has the same construction as the Instruction Packet with the addition of the ERROR field.

Header 1Header 2Header 3ReservedPacket IDLength 1Length 2InstructionERRPARAMPARAMPARAMCRC 1CRC 2
0xFF0xFF0xFD0x00IDLen_LLen_HInstructionErrorParam 1...Param NCRC_LCRC_H

Instruction​

The instruction for Status Packets is 0x55 (Status), this should be included as the instruction for all returned status packets.

Error​

The field that indicates the result of the received Instruction Packet.

Bit 7Bit 6 ~ Bit 0
AlertError Number
  • Alert : When there is some hard ware issue with the Device, this field is set as 1. Checking the Hardware error status value of the Control Table can indicate the cause of the problem.
  • Error Number : When there has been an Error in the processing of the Instruction Packet.
Error NumberErrorDescription
0x01Result FailFailed to process the sent Instruction Packet
0x02Instruction ErrorAn undefined Instruction has been used
Action has been used without Reg Write
0x03CRC ErrorThe CRC of the sent Packet does not match the expected value
0x04Data Range ErrorData to be written to the specified Address is outside the range of the minimum/maximum value
0x05Data Length ErrorAttempted to write Data that is shorter than the required data length of the specified Address
(ex: when you attempt to only use 2 bytes of a register that has been defined as 4 bytes)
0x06Data Limit ErrorData to be written to the specified Address is outside of the configured Limit value
0x07Access ErrorAttempted to write a value to an Address that is Read Only or has not been defined
Attempted to read a value from an Address that is Write Only or has not been defined
Attempted to write a value to an EEPROM register while Torque was Enabled.

Parameters​

This section contains the data used as an argument to the instruction included in the packet, and may differ in length and content depending on the type of packet sent.

warning

WARNING: The method of expressing negative numbers in this data field may differ for each product. Please refer to the eManual page for your specific product for more information.

Response Policy​

The method of response to received Instructions can be modified using the value of the Status Return Level Control Table item. For more details, see the Status Return Level section of the eManual page for your specific actuator.

warning

WARNING: The DYNAMIXEL Broadcast ID (254 (0xFE)) will only return Status Packets for Ping, Sync Read and Bulk Read commands, other Instructions aside from Ping, Sync Read and Bulk Read will not return Status Packets when sent to the Broadcast ID.

Packet Process

Transmission Process​

  1. Generate basic packet structure including required parameters.
  2. Apply Byte Stuffing to ensure that packets are processed successfully.
  3. Update packet length to include any stuffed bytes.
  4. Calculate final CRC with byte stuffing applied.
note

NOTICE: Byte stuffing is a method of adding additional data to generated instruction packets to ensure that the packets are processed successfully. When the byte pattern "0xFF 0xFF 0xFD" appears in a packet, byte stuffing adds 0xFD to the end of the pattern to convert it to "0xFF 0xFF 0xFD 0xFD" to ensure that it is not interpreted as the header at the start of another packet.

Processing Order of Reception​

  1. Search for packet Header (0xFF 0xFF 0xFD), ignoring any found Byte Stuffing (0xFF 0xFF 0xFD 0xFD).
  2. If the Packet ID is valid, prepare to receive additional transmission data the size of Length.
  3. Calculate the CRC with the received Packet with Byte Stuffing included, if the CRC matches, remove byte stuffing from received packet.
  4. Execute received packet.

Instruction Details

Note that given examples use the following abbreviations for each packet section:

  • Header : H
  • Reserved: RSRV
  • Length: LEN
  • Instruction: INST
  • Error: ERR
  • Param: P

Ping (0x01)​

Description​

  • Used to check for the existence of a Device and retrieve basic information.
  • Regardless of the Status Return Level of the Device a Status Packet will always be sent in response to a ping packet.
  • When a Ping command is sent to the Broadcast ID - 0xFE all connected devices will respond with a status packet.

Packet Parameters​

note

Note : A Status Packet will be received from each connected Device.

Status PacketDescription
Parameter 1Model Number LSB
Parameter 2Model Number MSB
Parameter 3Version of Firmware

Example 1​

Conditions​

  • ID1(XM430-W210) : Model Number 1030(0x0406), Firmware Version 38(0x26)
  • Instruction Packet ID : 1

Ping Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTCRC 1CRC 2
0xFF0xFF0xFD0x000x010x030x000x010x190x4E

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRP1P2P3CRC 1CRC 2
0xFF0xFF0xFD0x000x010x070x000x550x000x060x040x260x650x5D

Example 2​

Conditions​

  • ID1(XM430-W210) : Model Number 1030(0x0406), Firmware Version 38(0x26)
  • ID2(XM430-W210) : Model Number 1030(0x0406), Firmware Version 38(0x26)
  • Instruction Packet ID : 254(Broadcast ID)

Ping Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTCRC 1CRC 2
0xFF0xFF0xFD0x000xFE0x030x000x010x310x42

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRP1P2P3CRC 1CRC 2
0xFF0xFF0xFD0x000x010x070x000x550x000x060x040x260x650x5D

ID 2 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRP1P2P3CRC 1CRC 2
0xFF0xFF0xFD0x000x020x070x000x550x000x060x040x260x6F0x6D

Read (0x02)​

Description​

  • Reads a specified value from the Control Table.
  • Read Instructions are not executed when sent to the Broadcast ID(254 (0xFE))
warning

WARNING: The method of expressing negative numbers data fields may differ for each product. Please refer to the eManual page for your specific product for more information.

note

Note: If the requested item is outside the range of the Control Table, the returned Status packet will include an Access Error in its error field, and return with with no parameters.

Packet Parameters​

Instruction PacketDescription
Parameter 1Low-order byte from the starting address
Parameter 2High-order byte from the starting address
Parameter 3Low-order byte from the data length (X)
Parameter 4High-order byte from the data length (X)
Status PacketDescription
Parameter 1First Byte
Parameter 2Second Byte
......
Parameter XX-th Byte

Example​

Conditions​

  • ID1(XM430-W210) : Present Position(132, 0x0084, 4[byte]) = 166(0x000000A6)

Read Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4CRC 1CRC 2
0xFF0xFF0xFD0x000x010x070x000x020x840x000x040x000x1D0x15

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRP1P2P3P4CRC 1CRC 2
0xFF0xFF0xFD0x000x010x080x000x550x000xA60x000x000x000x8C0xC0

Write (0x03)​

Description​

warning

WARNING: The method of expressing negative numbers data fields may differ for each product. Please refer to the eManual page for your specific product for more information.

Packet Parameters​

Instruction PacketDescription
Parameter 1Low-order byte from the starting address
Parameter 2High-order byte from the starting address
Parameter 2+1First Byte
Parameter 2+2Second Byte
......
Parameter 2+XX-th Byte

Example​

Conditions​

  • ID1(XM430-W210) : Write 512(0x00000200) to Goal Position(116, 0x0074, 4[byte])

Write Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5P6CRC 1CRC 2
0xFF0xFF0xFD0x000x010x090x000x030x740x000x000x020x000x000xCA0x89

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRCRC 1CRC 2
0xFF0xFF0xFD0x000x010x040x000x550x000xA10x0C

Reg Write (0x04)​

Description​

  • Instruction similar to a Write Instruction, but with an improved synchronization characteristic. Write Instructions are executed immediately when an Instruction Packet is received, while Reg Write saves the command to be executed later in response to an Action instruction.
  • By using Reg Write and Action Instructions, one can operate multiple devices simultaneously.
  • Reg Write Instruction registers the Instruction Packet to a standby status, and sets Control table Registered Instruction to ‘1’.
  • When an Action Instruction is received, the registered Packet is executed, and sets Control Table Registered Instruction to ‘0’.

Packet Parameters​

Instruction PacketDescription
Parameter 1Low-order byte from the starting address
Parameter 2High-order byte from the starting address
Parameter 2+1First Byte
Parameter 2+2Second Byte
......
Parameter 2+XX-th Byte

Example​

Condition​

  • ID1(XM430-W210) : Write 200(0x000000C8) to Goal Velocity(104, 0x0068, 4[byte])

Reg Write Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5P6CRC 1CRC 2
0xFF0xFF0xFD0x000x010x090x000x040x680x000xC80x000x000x000xAE0x8E

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRCRC 1CRC 2
0xFF0xFF0xFD0x000x010x040x000x550x000xA10x0C

Action (0x05)​

Description​

  • Instruction that executes the Packet that has been registered using Reg Write Instruction
  • When controlling multiple devices using Write Instruction, there will be a difference in the time of execution between the first device that receives the Packet and the last device that receives the Packet.
  • By using Reg Write and Action Instruction, one can operate multiple devices simultaneously.

Example​

Condition​

  • ID1(XM430-W210) : Instruction has been already registered by the Reg Write Instruction.

Action Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTCRC 1CRC 2
0xFF0xFF0xFD0x000x010x030x000x050x020xCE

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRCRC 1CRC 2
0xFF0xFF0xFD0x000x010x040x000x550x000xA10x0C

Factory Reset (0x06)​

Description​

  • Instruction that resets the Control Table to its initial factory default settings.
  • When Factory Reset (0x06) Instruction is performed, the device is rebooted and the LED blinks four times in a row to indicate a successful reset.
warning

WARNING: When the Packet ID is the Broadcast ID 0xFE and the configured Option is Reset All 0xFF, the Factory Reset Instruction(0x06) will NOT be executed. This safety feature is present in MX(2.0) FW42, X-series FW42 or above.

Parameters​

Instruction PacketDescription
Parameter 10xFF : Reset all
0x01 : Reset all except ID
0x02 : Reset all except ID and Baudrate

Example​

Conditions​

  • ID1(XM430-W210) : Apply reset with option 0x01(Reset all except ID)

Factory Reset Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1CRC 1CRC 2
0xFF0xFF0xFD0x000x010x040x000x060x010xA10xE6

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRCRC 1CRC 2
0xFF0xFF0xFD0x000x010x040x000x550x000xA10x0C

Reboot (0x08)​

Description​

  • Instruction to reboot the device

Example​

Conditions​

  • ID1(XM430-W210)

Reboot Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTCRC 1CRC 2
0xFF0xFF0xFD0x000x010x030x000x080x2F0x4E

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRCRC 1CRC 2
0xFF0xFF0xFD0x000x010x040x000x550x000xA10x0C

Clear (0x10)​

Description​

  • This instruction resets the multi-turn position information of the device.

Parameters​

P1P2 ~ P5Description
0x01Fixed Values
(0x44 0x58 0x4C 0x22)		Reset the Present Position value to an absolute value within one rotation (0-4095).
The Clear instruction can only be executed when the DYNAMIXEL is stopped.
Note that if DYNAMIXEL is in motion and the Clear Instruction packet is sent, Result Fail (0x01) will be returned in the Error field of the Status Packet.
0x02Fixed value
(0x45 0x52 0x43 0x4C)		Clear any registered errors that have occurred.
If an error cannot be cleared or the conditions for clearance are not met, the error will not be cleared, and Result Fail (0x01) will be returned in the Error field of the Status Packet.
This feature is supported only by the DYNAMIXEL Y series.
...-Reserved
0xFF-Reserved

Example​

Conditions​

  • ID1(XM430-W210) : Resets multi turn revolution information

Clear Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5CRC 1CRC 2
0xFF0xFF0xFD0x000x010x080x000x100x010x440x580x4C0x220xB10xDC

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRCRC 1CRC 2
0xFF0xFF0xFD0x000x010x040x000x550x000xA10x0C

Control Table Backup (0x20)​

Description​

  • Instruction to store current Control Table configuration data to a Backup area, or to restore previous EEPROM data backups.
  • Control Table Backup works properly only if Torque Enable in RAM area is set to '0' (Torque Off status). If Torque Enable is set to '1' (Torque On), a Status Packet with Result Fail will be returned.
  • Supported DYNAMIXELs: X430/540 Series(Fw v45 or above), X330 Series(Fw v46 or above), P Series(Fw v12 or above).
  • Available items in Control Table for data backup:
    • All Data in EEPROM
    • Velocity P.I Gains
    • Position P.I.D Gains
    • Feedforward 1st & 2nd Gains
    • Profile Acceleration
    • Profile Velocity
    • Indirect Addresses (Except DYNAMIXEL-P Series)
note

Note

Parameters​

P1P2 ~ P5Description
0x01Fixed Values
(0x43 0x54 0x52 0x4C)		Store current Control Table status data to a Backup area
0x02Fixed Values
(0x43 0x54 0x52 0x4C)		Restore EEPROM data from Backup area.
After processing packets, DYNAMIXEL reboots itself
0x03-Reserved
⋯-Reserved
0xFF-Reserved

Example​

Example 1 Conditions​

  • ID 1(XC330-T288) : Backup the Control Table.

Control Table Backup Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5CRC1CRC2
0xFF0xFF0xFD0x000x010x080x000x200x010x430x540x520x4C0x160xF5

ID1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRCRC1CRC2
0xFF0xFF0xFD0x000x010x040x000x550x000xA10x0C

Example 2 Conditions​

  • ID1(XC330-T288) : Restoring EEPROM data
  • DYNAMIXEL will reboot after a successful restoration.

Control Table EEPROM Restoring Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5CRC1CRC2
0xFF0xFF0xFD0x000x010x080x000x200x020x430x540x520x4C0x9E0xF5

ID1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRCRC1CRC2
0xFF0xFF0xFD0x000x010x040x000x550x000xA10x0C

Sync Read (0x82)​

Description​

  • Instruction to read data from multiple devices simultaneously using one Instruction Packet
  • The Address and Data Length of the data must all be the same.
  • If the Address of the data is not continual, an Indirect Address can be used.
  • Status Packet will be returned in order, according to input ID in the Instruction Packet.
  • The Packet ID must be 0xFE (Broadcast ID)

Parameters​

Instruction PacketDescription
Parameter 1Low-order byte from the starting address
Parameter 2High-order byte from the starting address
Parameter 3Low-order byte from the data length(X)
Parameter 4High-order byte from the data length(X)
Parameter 4+1ID of the 1st Device
Parameter 4+2ID of the 2nd Device
......
Parameter 4+XID of the X-th Device
Status PacketDescription
Parameter 1Frist Byte
Parameter 2Second Byte
......
Parameter XX-th Byte
note

Note : Each device individually returns a Status Packet for Sync Read instructions.

Example​

Conditions​

  • ID1(XM430-W210) : Present Position(132, 0x0084, 4[byte]) = 166(0x000000A6)
  • ID2(XM430-W210) : Present Position(132, 0x0084, 4[byte]) = 2,079(0x0000081F)

Sync Read Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5P6CRC 1CRC 2
0xFF0xFF0xFD0x000xFE0x090x000x820x840x000x040x000x010x020xCE0xFA

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRP1P2P3P4CRC 1CRC 2
0xFF0xFF0xFD0x000x010x080x000x550x000xA60x000x000x000x8C0xC0

ID 2 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRP1P2P3P4CRC 1CRC 2
0xFF0xFF0xFD0x000x020x080x000x550x000x1F0x080x000x000xBA0xBE

Sync Write (0x83)​

Description​

  • Instruction to control multiple devices simultaneously using one Instruction Packet
  • The Address and Data Length of the data must all be the same.
  • If the Address of the data is not continual, an Indirect Address can be used.
  • The Packet ID must be 0xFE (Broadcast ID)

Parameters​

Instruction PacketDescription
Parameter 1Low-order byte from the starting address
Parameter 2High-order byte from the starting address
Parameter 3Low-order byte from the data length(X)
Parameter 4High-order byte from the data length(X)
Parameter 5[1st Device] ID
Parameter 5+1[1st Device] 1st Byte
Parameter 5+2[1st Device] 2nd Byte
...[1st Device]...
Parameter 5+X[1st Device] X-th Byte
Parameter 6[2nd Device] ID
Parameter 6+1[2nd Device] 1st Byte
Parameter 6+2[2nd Device] 2nd Byte
...[2nd Device]...
Parameter 6+X[2nd Device] X-th Byte
......

Example​

Conditions​

  • ID1(XM430-W210) : Write 150(0x00000096) to Goal Position(116, 0x0074, 4[byte])
  • ID2(XM430-W210) : Write 170(0x000000AA) to Goal Position(116, 0x0074, 4[byte])

Sync Write Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4
0xFF0xFF0xFD0x000xFE0x110x000x830x740x000x040x00
P5P6P7P8P9P10P11P12P13P14CRC 1CRC 2
0x010x960x000x000x000x020xAA0x000x000x000x820x87

Fast Sync Read (0x8A)​

Description​

  • Enhanced Instruction for faster communication compared to Sync Read
  • One Status Packet is built and returned for all DYNAMIXELs if using Fast Sync Read Instruction regardless of number of DYNAMIXELs chained, as if one DYNAMIXEL has returned a single Status Packet.
  • Instruction Packet is formatted in the same way as Sync Read
  • Supported DYNAMIXELs:
    • X430/540 Series (Fw v45 or above, 2XL/2XC Not Supported)
    • X330 (Fw v46 or above)
    • P Series (Fw v12 or above)
    • RH-P12-RN(A) (Fw v13 or above)
note

Note: DYNAMIXEL Tips | Use Fast Sync and Fast Bulk Read Instruction for Speedy Communication

Parameter​

Instruction PacketDescription
Parameter 1Low-order byte from the starting address
Parameter 2High-order byte from the starting address
Parameter 3Low-order byte from the data length(X)
Parameter 4High-order byte from the data length(X)
Parameter 4+11st Device ID
Parameter 4+22nd Device ID
⋯⋯
Parameter 4+nNnd Device ID
Status PacketDescription
Parameter 11st Device ID
Parameter 21st Device First Byte
Parameter 31st Device Second Byte
⋯⋯
Parameter X1st Device X-th Byte
Parameter X+11st Device Low-order byte from CRC
Parameter X+21st Device High-order byte from CRC
Parameter X+32nd Device Error
Parameter X+42nd Device ID
Parameter X+4+12nd Device First Byte
Parameter X+4+22nd Device Second Byte
⋯⋯
Parameter 2X+42nd Device X-th Byte
Parameter 2X+4+12nd Device Low-order byte from CRC
Parameter 2X+4+22nd Device High-order byte from CRC
⋯⋯
Parameter nX+4Nnd Device X-th Byte
note

Note: CRC values are used for internal calculation in DYNAMIXEL to confirm packet integrity between DYNAMIXELs. You can let the main controller check CRC only at the end of Status Packet.

note

Note: Each device respectively returns a particular part of Status Packet in response to Fast Sync Read Instruction. For more details, see Example below.

note

Note: Fast Sync Read Status Packet does not perform Byte Stuffing(0xFD) process.

Example​

Example Description​

  • ID3(XC330-T288) : Present Position(132, 0x0084, 4[byte]) = 166(0x000000A6)
  • ID7(XC330-T288) : Present Position(132, 0x0084, 4[byte]) = 2,079(0x0000081F)
  • ID4(XC330-T288) : Present Position(132, 0x0084, 4[byte]) = 1,023(0x000003FF)

Fast Sync Read Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5P6P7CRC1CRC2
0xFF0xFF0xFD0x000xFE0x0A0x000x8A0x840x000x040x000x030x070x040x200xF2

ID 3 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRID1D1D2D3D4CRC1CRC2
0xFF0xFF0xFD0x000xFE0x190x000x550x000x030xA60x000x000x000x840x08

ID 7 Status Packet​

ERRID2D1D2D3D4CRC1CRC2
0x000x070x1F0x080x000x000x160xCA

ID 4 Status Packet​

ERRID3D1D2D3D4CRC1CRC2
0x000x040xFF0x030x000x000xD10x9E

Bulk Read (0x92)​

Description​

  • Similar to Sync Read, this is an Instruction to read data from multiple devices simultaneously using one Instruction Packet
  • This Instruction can be used even if the Address and Data Length of the data for each device are not all the same.
  • The same ID cannot be used multiple times in the Parameter. In other words, it can only read once from each individual device.
  • Status Packet will be returned in order, according to input ID in the Instruction Packet.
  • If the Address of the data is not continual, an Indirect Address can be used.
  • The Packet ID must be 0xFE (Broadcast ID)

Parameters​

Instruction PacketDescription
Parameter 1[1st Device] ID
Parameter 2[1st Device] Low-order byte from the starting address
Parameter 3[1st Device] High-order byte from the starting address
Parameter 4[1st Device] Low-order byte from the data
Parameter 5[1st Device] High-order byte from the data
Parameter 6[2nd Device] ID
Parameter 7[2nd Device] Low-order byte from the starting address
Parameter 8[2nd Device] High-order byte from the starting address
Parameter 9[2nd Device] Low-order byte from the data
Parameter 10[2nd Device] High-order byte from the data
......
Status PacketDescription
Parameter 11st Byte
Parameter 22nd Byte
......
Parameter XX-th Byte
note

Note : Each device individually returns Status Packet for Bulk Read instruction. See the Example below for more details.

Example​

Condition​

  • ID1(XM430-W210) : Present Voltage(144, 0x0090, 2[byte]) = 119(0x0077)
  • ID2(XM430-W210) : Present Temperature(146, 0x0092, 1[byte]) = 36(0x24)

Bulk Read Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5
0xFF0xFF0xFD0x000xFE0x0D0x000x920x010x900x000x020x00
P6P7P8P9P10CRC 1CRC 2
0x020x920x000x010x000x1A0x05

ID 1 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRP1P2CRC 1CRC 2
0xFF0xFF0xFD0x000x010x060x000x550x000x770x000xC30x69

ID 2 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRP1CRC 1CRC 2
0xFF0xFF0xFD0x000x020x050x000x550x000x240x8B0xA9

Bulk Write (0x93)​

Description​

  • Similar to Sync Write, this is an Instruction to control multiple devices simultaneously using one Instruction Packet
  • This Instruction can be used even if the Address and Data Length of the data for each device are not all the same.
  • The same ID cannot be used multiple times in the Parameter. In other words, it can only write once for each individual device.
  • If the Address of the data is not continual, an Indirect Address can be used.
  • The Packet ID must be 0xFE (Broadcast ID)

Parameters​

Instruction PacketDescription
Parameter 1[1st Device] ID
Parameter 2[1st Device] Low-order byte from the starting address
Parameter 3[1st Device] High-order byte from the starting address
Parameter 4[1st Device] Low-order byte from the data length(X)
Parameter 5[1st Device] High-order byte from the data length(X)
Parameter 5+1[1st Device] 1st Byte
Parameter 5+2[1st Device] 2nd Byte
......
Parameter 5+X[1st Device] X-th Byte
Parameter 6+X[2nd Device] ID
Parameter 7+X[2nd Device] Low-order byte from the starting address
Parameter 8+X[2nd Device] High-order byte from the starting address
Parameter 9+X[2nd Device] Low-order byte from the data length(X)
Parameter 10+X[2nd Device] High-order byte from the data length(X)
Parameter 10+X+1[2nd Device] 1st Byte
Parameter 10+X+2[2nd Device] 2nd Byte
......
Parameter 10+X+Y[2nd Device] Y-th Byte
......

Example​

Condition​

  • ID1(XM430-W210) : Set Max Voltage Limit(32, 0x0020, 2[byte]) to 160(0x00A0)
  • ID2(XM430-W210) : Set Temperature Limit(31, 0x001F, 1[byte]) to 80(0x50)

Bulk Write Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5P6P7
0xFF0xFF0xFD0x000xFE0x100x000x930x010x200x000x020x000xA00x00
P8P9P10P11P12P13CRC 1CRC 2
0x020x1F0x000x010x000x500xB70x68

Fast Bulk Read (0x9A)​

Description​

  • Enhanced Instruction for faster communication compared to Bulk Read.
  • One Status Packet is built and returned for all DYNAMIXELs using Fast Bulk Read Instruction regardless of number of DYNAMIXELs chained, as if one DYNAMIXEL returned a single Status Packet.
  • Instruction Packet is formatted in the same way as Bulk Read
  • Supported DYNAMIXELs:
    • X430/540 Series (Fw v45 or above, 2XL/2XC Not Supported)
    • X330 (Fw v46 or above)
    • P Series (Fw v12 or above)
    • RH-P12-RN(A) (Fw v13 or above)
note

Note: DYNAMIXEL Tips | Use Fast Sync and Fast Bulk Read Instruction for Speedy Communication

Parameters​

Instruction PacketDescription
Parameter 11st Device ID
Parameter 21st Device Low-order byte from the starting address
Parameter 31st Device High-order byte from the starting address
Parameter 41st Device Low-order byte from the data length(X1)
Parameter 51st Device High-order byte from the data length(X1)
Parameter 62nd Device ID
Parameter 72nd Device Low-order byte from the starting address
Parameter 82nd Device High-order byte from the starting address
Parameter 92nd Device Low-order byte from the data length(X2)
Parameter 102nd Device High-order byte from the data length(X2)
Status PacketDescription
Parameter 11st Device ID
Parameter 21st Device First Byte
Parameter 31st Device Second Byte
⋯⋯
Parameter X11st Device X1-th Byte
Parameter X1+11st Device Low-order byte from CRC
Parameter X1+21st Device High-order byte from CRC
Parameter X1+32nd Device Error
Parameter X1+42nd Device ID
Parameter X1+4+12nd Device First Byte
Parameter X1+4+22nd Device Second Byte
⋯⋯
Parameter X1+4+X22nd Device X2-th Byte
Parameter X1+4+X2+12nd Device Low-order byte from CRC
Parameter X1+4+X2+22nd Device High-order byte from CRC
⋯⋯
Parameter X1+4+X2+
⋯ 4+Xn		Nnd Device Xn-th Byte
note

Note: CRC values are used for internal calculation in DYNAMIXEL to confirm packet integrity between DYNAMIXELs. You can let the main controller check CRC only at the end of Status Packet.

note

Note: Each device respectively returns a particular part of Status Packet in response to Fast Bulk Read Instruction. For more details, see Example below.

note

Note: Status Packet responded from Fast Bulk Read does not perform Byte Stuffing(0xFD) process.

Example​

Example Description​

  • ID3(XC330-T288) : Present Position(132, 0x0084, 4[byte]) = 166(0x000000A6)
  • ID7(XC330-T288) : Present PWM(124, 0x007C, 2[byte]) = 421(0x01A5)
  • ID4(XC330-T288) : Present Temperature(146, 0x0092, 1[byte]) = 31(0x1F)

Fast Bulk Read Instruction Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTP1P2P3P4P5P6P7P8
0xFF0xFF0xFD0x000xFE0x120x000x9A0x030x840x000x040x000x070x7C0x00
P9P10P11P12P13P14P15CRC1CRC2
0x020x000x040x920x000x010x000xDA0x2D

ID 3 Status Packet​

H1H2H3RSRVPacket IDLEN1LEN2INSTERRID1D1D2D3D4CRC1CRC2
0xFF0xFF0xFD0x000xFE0x140x000x550x000x030xA60x000x000x000x670xA4

ID 7 Status Packet​

ERRID2D1D2CRC1CRC2
0x000x070xA50x010x240x74

ID 4 Status Packet​

ERRID2D1CRC1CRC2
0x000x040x1F0xD90xC1
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