Edit on GitHub

XH540-W270-T/R

Specifications

Item	Specifications
MCU	ST CORTEX-M3 (STM32F103C8 @ 72 [Mhz], 32Bit)
Position Sensor	Contactless absolute encoder (12Bit, 360 [°]) Maker : ams(www.ams.com), Part No : AS5045
Motor	Maxon
Baud Rate	9,600 [bps] ~ 4.5 [Mbps]
Control Algorithm	PID control
Resolution	4096 [pulse/rev]
Backlash	15 [arcmin] (0.25 [°])
Operating Modes	Current Control Mode Velcoity Control Mode Position Control Mode (0 ~ 360 [°]) Extended Position Control Mode (Multi-turn) Current-based Position Control Mode PWM Control Mode (Voltage Control Mode)
Weight	165 [g]
Dimensions (W x H x D)	33.5 x 58.5 x 44 [mm]
Gear Ratio	272.5 : 1
Stall Torque	9.2 [Nm] (at 11.1 [V], 4.5 [A]) 9.9 [Nm] (at 12.0 [V], 4.9 [A]) 11.7 [Nm] (at 14.8 [V], 5.9 [A])
No Load Speed	36 [rev/min] (at 11.1 [V]) 39 [rev/min] (at 12.0 [V]) 46 [rev/min] (at 14.8 [V])
Radial Load	40 [N] (10 [mm] away from the horn)
Axial Load	20 [N]
Operating Temperature	-5 ~ +80 [°C]
Input Voltage	10.0 ~ 14.8 [V] (Recommended : 12.0 [V])
Command Signal	Digital Packet
Protocol Type	TTL Half Duplex Asynchronous Serial Communication with 8bit, 1stop, No Parity RS485 Asynchronous Serial Communication with 8bit, 1stop, No Parity
Physical Connection	RS485 / TTL Multidrop Bus
ID	253 ID (0 ~ 252)
Feedback	Position, Velocity, Current, Realtime tick, Trajectory, Temperature, Input Voltage, etc
Part Material	Full Metal Gear Metal (Front, Middle), Engineering Plastic (Back)
Standby Current	40 [mA]

Performance Graph

NOTE : The Max Torque and the Stall Torque of Performance Graph are different in measurement methods.
Stall torque is a measured value of the momentary torque that it can reach. This is generally how RC servos are measured.
The Performance graph is also called as N-T curves, which is measured with the gradually increasing load.
The actual motor operation environment is closer to the performance graph, not stall torque method.
For this reason, the performance graph is broadly used in the industrial field.
Generally, Max Torque of the Performance Graph is less than the Stall Torque.

Control Table

The Control Table is a structure of data implemented in the device. Users can read a specific Data to get status of the device with Read Instruction Packets, and modify Data as well to control the device with WRITE Instruction Packets.

Control Table, Data, Address

The Control Table is a structure that consists of multiple Data fields to store status or to control the device. Users can check current status of the device by reading a specific Data from the Control Table with Read Instruction Packets. WRITE Instruction Packets enable users to control the device by changing specific Data in the Control Table. The Address is a unique value when accessing a specific Data in the Control Table with Instruction Packets. In order to read or write data, users must designate a specific Address in the Instruction Packet. Please refer to Protocol 2.0 for more details about Instruction Packets.

NOTE : Two’s complement is applied for the negative value. For more information, please refer to Two’s complement from Wikipedia.

Area (EEPROM, RAM)

The Control Table is divided into 2 Areas. Data in the RAM Area is reset to initial values when the power is reset(Volatile). On the other hand, data in the EEPROM Area is maintained even when the device is powered off(Non-Volatile).
Data in the EEPROM Area can only be written to if Torque Enable(64) is cleared to ‘0’(Off).

Size

The Size of data varies from 1 ~ 4 bytes depend on their usage. Please check the size of data when updating the data with an Instruction Packet. For data larger than 2 bytes will be saved according to Little Endian.

Access

The Control Table has two different access properties. ‘RW’ property stands for read and write access permission while ‘R’ stands for read only access permission. Data with the read only property cannot be changed by the WRITE Instruction. Read only property(‘R’) is generally used for measuring and monitoring purpose, and read write property(‘RW’) is used for controlling device.

Initial Value

Each data in the Control Table is restored to initial values when the device is turned on. Default values in the EEPROM area are initial values of the device (factory default settings). If any values in the EEPROM area are modified by a user, modified values will be restored as initial values when the device is turned on. Initial Values in the RAM area are restored when the device is turned on.

Control Table of EEPROM Area

Address	Size (Byte)	Data Name	Access	Default Value	Range	Unit
0	2	Model Number	R	1,100	-	-
2	4	Model Information	R	-	-	-
6	1	Firmware Version	R	-	-	-
7	1	ID	RW	1	0 ~ 253	-
8	1	Baud Rate	RW	1	0 ~ 7	-
9	1	Return Delay Time	RW	250	0 ~ 254	2 [μsec]
10	1	Drive Mode	RW	0	0 ~ 2	-
11	1	Operating Mode	RW	3	0 ~ 16	-
12	1	Secondary(Shadow) ID	RW	255	0 ~ 252	-
13	1	Protocol Version	RW	2	1 ~ 2	-
20	4	Homing Offset	RW	0	-1,044,479 ~ 1,044,479	1 [pulse]
24	4	Moving Threshold	RW	10	0 ~ 1,023	0.229 [rev/min]
31	1	Temperature Limit	RW	80	0 ~ 100	1 [°C]
32	2	Max Voltage Limit	RW	160	95 ~ 160	0.1 [V]
34	2	Min Voltage Limit	RW	95	95 ~ 160	0.1 [V]
36	2	PWM Limit	RW	885	0 ~ 885	0.113 [%]
38	2	Current Limit	RW	2,047	0 ~ 2,047	2.69 [mA]
44	4	Velocity Limit	RW	128	0 ~ 1,023	0.229 [rev/min]
48	4	Max Position Limit	RW	4,095	0 ~ 4,095	1 [pulse]
52	4	Min Position Limit	RW	0	0 ~ 4,095	1 [pulse]
56	1	External Port Mode 1	RW	3	0 ~ 3	-
57	1	External Port Mode 2	RW	3	0 ~ 3	-
58	1	External Port Mode 3	RW	3	0 ~ 3	-
63	1	Shutdown	RW	52	-	-

Control Table of RAM Area

Address	Size (Byte)	Data Name	Access	Default Value	Range	Unit
64	1	Torque Enable	RW	0	0 ~ 1	-
65	1	LED	RW	0	0 ~ 1	-
68	1	Status Return Level	RW	2	0 ~ 2	-
69	1	Registered Instruction	R	0	0 ~ 1	-
70	1	Hardware Error Status	R	0	-	-
76	2	Velocity I Gain	RW	1,920	0 ~ 16,383	-
78	2	Velocity P Gain	RW	100	0 ~ 16,383	-
80	2	Position D Gain	RW	0	0 ~ 16,383	-
82	2	Position I Gain	RW	0	0 ~ 16,383	-
84	2	Position P Gain	RW	800	0 ~ 16,383	-
88	2	Feedforward 2nd Gain	RW	0	0 ~ 16,383	-
90	2	Feedforward 1st Gain	RW	0	0 ~ 16,383	-
98	1	Bus Watchdog	RW	0	1 ~ 127	20 [μsec]
100	2	Goal PWM	RW	-	-PWM Limit(36) ~ PWM Limit(36)	-
102	2	Goal Current	RW	-	-Current Limit(38) ~ Current Limit(38)	2.69 [mA]
104	4	Goal Velocity	RW	-	-Velocity Limit(44) ~ Velocity Limit(44)	0.229 [rev/min]
108	4	Profile Acceleration	RW	0	0 ~ 32,767 0 ~ 32,737	214.577 [rev/min2] 1 [ms]
112	4	Profile Velocity	RW	0	0 ~ 32,767	0.229 [rev/min]
116	4	Goal Position	RW	-	Min Position Limit(52) ~ Max Position Limit(48)	1 [pulse]
120	2	Realtime Tick	R	-	0 ~ 32,767	1 [msec]
122	1	Moving	R	0	0 ~ 1	-
123	1	Moving Status	R	0	-	-
124	2	Present PWM	R	-	-	-
126	2	Present Current	R	-	-	2.69 [mA]
128	4	Present Velocity	R	-	-	0.229 [rev/min]
132	4	Present Position	R	-	-	1 [pulse]
136	4	Velocity Trajectory	R	-	-	0.229 [rev/min]
140	4	Position Trajectory	R	-	-	1 [pulse]
144	2	Present Input Voltage	R	-	-	0.1 [V]
146	1	Present Temperature	R	-	-	1 [°C]
152	2	External Port Data 1	RW	-	-	-
154	2	External Port Data 2	RW	-	-	-
156	2	External Port Data 3	RW	-	-	-
168	2	Indirect Address 1	RW	224	64 ~ 661	-
170	2	Indirect Address 2	RW	225	64 ~ 661	-
172	2	Indirect Address 3	RW	226	64 ~ 661	-
…	…	…	…	…	-	-
218	2	Indirect Address 26	RW	249	64 ~ 661	-
220	2	Indirect Address 27	RW	250	64 ~ 661	-
222	2	Indirect Address 28	RW	251	64 ~ 661	-
224	1	Indirect Data 1	RW	0	0 ~ 255	-
225	1	Indirect Data 2	RW	0	0 ~ 255	-
226	1	Indirect Data 3	RW	0	0 ~ 255	-
…	…	…	…	…	-	-
249	1	Indirect Data 26	RW	0	0 ~ 255	-
250	1	Indirect Data 27	RW	0	0 ~ 255	-
251	1	Indirect Data 28	RW	0	0 ~ 255	-
578	2	Indirect Address 29	RW	634	64 ~ 661	-
580	2	Indirect Address 30	RW	635	64 ~ 661	-
582	2	Indirect Address 31	RW	636	64 ~ 661	-
…	…	…	…	…	-	-
628	2	Indirect Address 54	RW	659	64 ~ 661	-
630	2	Indirect Address 55	RW	660	64 ~ 661	-
632	2	Indirect Address 56	RW	661	64 ~ 661	-
634	1	Indirect Data 29	RW	0	0 ~ 255	-
635	1	Indirect Data 30	RW	0	0 ~ 255	-
636	1	Indirect Data 31	RW	0	0 ~ 255	-
…	…	…	…	…	-	-
659	1	Indirect Data 54	RW	0	0 ~ 255	-
660	1	Indirect Data 55	RW	0	0 ~ 255	-
661	1	Indirect Data 56	RW	0	0 ~ 255	-

CAUTION : Protocol 1.0 does not support addresses greater than 256. Therefore, Indirect Address 29 ~ 56 and Indirect Data 29 ~ 56 can only be accessed with Protocol 2.0.

Control Table Description

CAUTION : Data in the EEPROM Area can only be written when the value of Torque Enable(64) is cleared to ‘0’.

Model Number(0)

This address stores model number of the DYNAMIXEL.

Firmware Version(6)

This address stores firmware version of the DYNAMIXEL.

ID(7)

The ID is a unique value in the network to identify each DYNAMIXEL with an Instruction Packet. 0~252 (0xFC) values can be used as an ID, and 254(0xFE) is occupied as a broadcast ID. The Broadcast ID(254, 0xFE) can send an Instruction Packet to all connected DYNAMIXELs simultaneously.

NOTE : Please avoid using an identical ID for multiple DYNAMIXELs. You may face communication failure or may not be able to detect Dynamixels with an identical ID.

Baud Rate(8)

Baud Rate determines serial communication speed between a controller and DYNAMIXELs.

Value	Baud Rate	Margin of Error
7	4.5M	0.000%
6	4M	0.000%
5	3M	0.000%
4	2M	0.000%
3	1M	0.000%
2	115,200	0.000%
1(Default)	57,600	0.000%
0	9,600	0.000%

NOTE : Less than 3% of the baud rate error margin will not affect to UART communication.

Return Delay Time(9)

After the DYNAMIXEL receives an Instruction Packet, it delays transmitting the Status Packet for Return Delay Time (9). For instance, if the Return Delay Time(9) is set to ‘10’, the Status Packet will be returned after 20[μsec] when the Instruction Packet is received.

Unit	Value Range	Description
2[μsec]	0 ~ 254	Default value ‘250’(500[μsec]), Maximum 508[μsec]

Drive Mode(10)

Drive Mode is availabe from the firmware version 38.

Bit	Item	Description
Bit 7(0x80)	-	Unused, always ‘0’
Bit 6(0x40)	-	Unused, always ‘0’
Bit 5(0x20)	-	Unused, always ‘0’
Bit 4(0x10)	-	Unused, always ‘0’
Bit 3(0x08)	-	Unused, always ‘0’
Bit 2(0x04)	Profile configureation	Velocity-based Profile(‘0’) : Create a Profile based on Velocity Time-based Profile(‘1’) : Create a Profile based on time ※ Please refer to Profile Velocity(112) for more details.
Bit 1(0x02)	Master/Slave Configuration (Dual Joint)	Master mode(‘0’) : Operate as a Master DYNAMIXEL Slave mode(‘1’) : Operate as a Slave DYNAMIXEL
Bit 0(0x01)	Direction of Rotation	Normal Mode(0): CCW(Positive), CW(Negative) Reverse Mode(1): CCW(Negative), CW(Positive)

NOTE : Setting Reverse mode(‘1’) for Direction of Rotation, DYNAMIXEL will switch rotating direction.
Therefore the direction of Position, Velocity, Current, PWM will be affected.
This feature can be very useful when configuring symmetrical joint system or wheel system.

Master / Slave Configuration (Dual Joint) is intended to control two DYNAMIXELs as a single module.
The Master DYNAMIXEL and the Slave DYNAMIXEL has to be interconnected with a Synchronization cable.
The Slave DYNAMIXEL is controlled by the PWM signal sent from the Master DYNAMIXEL via the synchronization cable.
Therefore, Goal Position, Goal Current, Goal PWM of the Slave DYNAMIXEL will be ignored in this mode.

Sync Cable	Description
General Mode	The Slave DYNAMIXEL is controlled by the PWM signal from the Master DYNAMIXEL. Master / Slave DYNAMIXELs have an identical rotational direction.
Reverse Mode(Twisted)	The Slave DYNAMIXEL is controlled by inverted PWM signal from the Master DYNAMIXEL. Master / Slave DYNAMIXELs have opposite rotational directions.

NOTE : If Master / Slave DYNAMIXELs are not mechanically connected to each other, each DYNAMIXEL could have minor differences during operation.
Please mount both DYNAMIXELs as shown in the below image.
Please refer to Connector Information for cable assembly.

Operating Mode(11)

Value	Operating Mode	Description
0	Current Control Mode	DYNAMIXEL only controls current(torque) regardless of speed and position. This mode is ideal for a gripper or a system that only uses current(torque) control or a system that has additional velocity/position controllers.
1	Velocity Control Mode	This mode controls velocity. This mode is identical to the Wheel Mode(endless) from existing DYNAMIXELs. This mode is ideal for wheel-type robots.
3(Default)	Position Control Mode	This mode controls position. This mode is identical to the Joint Mode from existing DYNAMIXELs. Operating position range is limited by Max Position Limit(48) and Min Position Limit(52). This mode is ideal for articulated robots that each joint rotates less than 360 degrees.
4	Extended Position Control Mode(Multi-turn)	This mode controls position. This mode is identical to the Multi-Turn Mode from existing DYNAMIXELs. 512 turns are supported(-256[rev] ~ 256[rev]). This mode is ideal for multi-turn wrists or conveyer systems or a system that requires an additional reduction gear.
5	Current-based Position Control Mode	This mode controls both position and current(torque). Up to 512 turns are supported(-256[rev] ~ 256[rev]). This mode is ideal for a system that requires both position and current control such as articulated robots or grippers.
16	PWM Control Mode (Voltage Control Mode)	This mode directly controls PWM output. (Voltage Control Mode)

NOTE : PWM is the abbreviation for Pulse Width Modulation that modulates PWM Duty to control motors.
The PWM Control Mode changes pulse width to control average supply voltage to the motor and this technique is widely used in the motor control field.
Therefore, PWM Control Mode uses Goal PWM(100) value to control supply voltage for DYNAMIXEL.
PWM Control Mode is similar to the Wheel Mode of DYNAMIXEL AX and RX series.

Secondary(Shadow) ID(12)

Set the Dynamixel’s Secondary ID. Secondary ID(12) is a value to identify each Dynamixel, just like the ID(7). However, unlike ID(7), Secondary ID(12) is not a unique value. Therefore, Dynamixels with the same Secondary ID value form a group. The differences between Secondary ID(12) and ID(7) are as follows :

1. Secondary ID(12) is not a unique value. i.e., a lot of Dynamixels may have the same Secondary ID value.
2. ID(7) has a higher priority than Secondary ID(12). i.e., if Secondary ID(12) and ID(7) are the same, ID(7) will be applied first.
3. The EEPROM area of the Control Table cannot be modified with Secondary ID(12). Only the RAM area can be modified.
4. If Instruction Packet ID is the same as Secondary ID(12), the Status Packet will not be returned.
5. If the value of Secondary ID(12) is 253 or higher, the Secondary ID function is deactivated.

Values	Description
0 ~ 252	Activate Secondary ID function
253 ~ 255	Deactivate Secondary ID function, Default value ‘255’

The following are examples of operation when there are five Dynamixels with ID (7) set from 1 to 5.

1. Set all five Dynamixels’ Secondary ID(12) to ‘5’.
2. Send Write Instruction Packet(ID = 1, LED(65) = 1).
3. Turn on LED of Dynamixel with ID ‘1’ and return the Status Packet.
4. Send Write Instruction Packet(ID = 5, LED(65) = 1).
5. Turn on LED on five Dynamixels. However, Status Packet of Dynamixel with ID ‘5’ will be returned.
6. Set the Secondary ID(12) of all five Dynamixels to ‘100’.
7. Send Write Instruction Packet(ID = 100, LED(65) = 0).
8. Turn off LED on five Dynamixels. However, as there is no Dynamixel with ID ‘100’, Status Packet is not returned.

Protocol Version(13)

Users can select Dynamixel protocol version (1.0 and 2.0).
Even if Protocol 1.0 is selected, Protocol 2.0 Control Table will be used.
It is recommended to use an identical protocol version for multiple Dynamixels.

Value	Protocol Version	Compatible Dynamixels
1	1.0	AX Series, DX Series, RX Series, EX Series, MX Series with Firmware below v39
2(default)	2.0	MX-28/64/106 with Firmware v39 or above, X Series, Pro Series

NOTE : The protocol 2.0 is greatly enhanced from the protocol 1.0. Accessing some of the Control Table area might be denied if protocol 1.0 is selected. This manual complies with protocol 2.0. Please refer to the Protocol 1.0 and Protocol 2.0 of e-Manual for more details about the protocol.

Homing Offset(20)

Users can adjust the Home position by setting Home Offset(20). The Homing Offset value is added to the Present Position(132). Present Position(132) = Actual Position + Homing Offset(20).

Unit	Value Range	Description
about 0.088 [°]	-1,044,479 ~ 1,044,479 (-255 ~ 255[rev])	4,096 resolution

NOTE : In case of the Position Control Mode(Joint Mode) that rotates less than 360 degrees, any invalid Homing Offset(20) values will be ignored(valid range : -1,024 ~ 1,024).

Moving Threshold(24)

This value helps to determine whether the Dynamixel is in motion or not.
When the absolute value of Present Velocity(128) is greater than the Moving Threshold(24), Moving(122) is set to ‘1’, otherwise it is cleared to ‘0’.

	Values	Description
Unit	about 0.229 rpm	All velocity related Data uses the same unit
Range	0 ~ 1,023	-

Temperature Limit(31)

This value limits operating temperature.
When the Present Temperature(146) that indicates internal temperature of Dynamixel is greater than the Temperature Limit(31), the Over Heating Error Bit(0x04) and Hardware Error Bit(0x80) in the Hardware Error Status(70) will be set.
If Overheating Error Bit(0x04) is configured in the Shutdown(63), Torque Enable(64) is cleared to ‘0’ and Torque will be disabled.
For more details, please refer to the Shutdown(63) section.

Unit	Value Range	Description
About 1°	0 ~ 100	0 ~ 100°

CAUTION : Do not set the temperature higher than the default value. When the temperature alarm shutdown occurs, wait 20 minutes to cool the temperature before re-use. Keep using the product when the temperature is high can cause severe damage.

Min/Max Voltage Limit(32, 34)

These values are maximum and minimum operating voltages. When present input voltage acquired from Present Input Voltage(144) exceeds the range of Max Voltage Limit(32) and Min Voltage Limit(34), Input Voltage Error Bit(0x01) in the Hardware Error Status(70) are set. If Input Voltage Error Bit(0x10) is configured in the Shutdown(63), Torque Enable(64) is cleared to ‘0’ and Torque is disabled. For more details, please refer to the Shutdown(63) section.

Unit	Value Range	Description
About 0.1V	95 ~ 160	9.5 ~ 16.0V

PWM Limit(36)

This value indicates maximum PWM output. Goal PWM(100) can’t be configured with any values exceeding PWM Limit(36). PWM Limit(36) is commonly used in all operating mode as an output limit, therefore decreasing PWM output will result in decreasing torque and velocity. For more details, please refer to the Gain section of each operating modes.

Values	Description
0(0%) ~ 885(100%)	885 = 100[%] output

Current Limit(38)

This value indicates maximum current(torque) output limit. Goal Current(102) can’t be configured with any values exceeding Current Limit(38). The Current Limit(38) is used in Torque Control Mode and Current-based Position Control Mode, therefore decreasing Current Limit(38) will result in decreasing torque of DYNAMIXEL. For more details, please refer to the Position PID Gain(80 ~ 84).

Unit	Value Range
about 2.69[mA]	0 ~ 2,047

NOTE : Current Limit(38) could be differ by each DYNAMIXEL so please check the Control Table.

Velocity Limit(44)

This indicates the maximum value of Goal Velocity(104). For more details, please refer to Goal Velocity(104).

Unit	Value Range
0.229rpm	0 ~ 1,023

NOTE: The default value of Velocity Limit(44) has been decreased since Firmware V42.

Min/Max Position Limit(48, 52)

These values limit maximum and minimum desired positions for Position Control Mode(Joint Mode) within the range of 1 rotation(0 ~ 4,095).
Therefore, Goal Position(116) should be configured within the position limit range.
These values are not used in Extended Position Control Mode and Current-based Position Control Mode.

Unit	Value Range
0.088 [°]	0 ~ 4,095(1 rotation)

NOTE : Max Position Limit(48) and Min Position Limit(52) are only used in Position Control Mode with a single turn.

External Port Mode 1,2,3(56,57,58)

External ports that can be used for various purposes are provided.
The property of each port is configured by the External Port Mode and data of external port is controlled by the External Port Data(152~157).
For more details, please refer to External Port Data(152~157).

External Port Mode	Mode	Description
0	AI(Analogue Input)	Converts External Port signal to 12[bit] digital value
1	DO_PP(Digital Output Push-Pull)	Use External Port as a digital output port(3.3V level)
2	DI_PU(Digital Input Pull-Up)	Use External Port as a digital input port Floating connection will be considered as ‘1’
3(default)	DI_PD(Digital Input Pull-Down)	Use External Port as a digital input port Floating connection will be considered as ‘0’

Shutdown(63)

The Dynamixel can protect itself by detecting dangerous situations that could occur during the operation.
Each Bit is inclusively processed with the ‘OR’ logic, therefore, multiple options can be generated.
For instance, when ‘0x05’ (binary : 00000101) is defined in Shutdown(63), Dynamixel can detect both Input Voltage Error(binary : 00000001) and Overheating Error(binary : 00000100).
If those errors are detected, Torque Enable(64) is cleared to ‘0’ and the motor output becomes 0[%].
REBOOT is the only method to reset Torque Enable(64) to ‘1’(Torque ON) after the shutdown.
The followings are detectable situations.

Bit	Item	Description
Bit 7	-	Unused, Always ‘0’
Bit 6	-	Unused, Always ‘0’
Bit 5	Overload Error(default)	Detect persistent load that exceeds maximum output
Bit 4	Electrical Shock Error(default)	Detect electric shock on the circuit or insufficient power to operate the motor
Bit 3	Motor Encoder Error	Detect malfunction of the motor encoder
Bit 2	OverHeating Error(default)	Detect internal temperature exceeds the configured operating temperature
Bit 1	-	Unused, Always ‘0’
Bit 0	Input Voltage Error	Detect input voltage exceeds the configured operating voltage

NOTE : If Shutdown occurs, LED will flicker every second.(Firmware v41 or above)

Torque Enable(64)

Controls Torque ON/OFF. Writing ‘1’ to this address will turn on the Torque and all Data in the EEPROM area will be protected.

Value	Description
0(Default)	Torque OFF(Free-run) and the motor does not generate torque
1	Torque ON and all Data in the EEPROM area will be locked

NOTE : Present Position(132) can be reset when Operating Mode(11) and Torque Enable(64) are updated. For more details, please refer to the Homing Offset(20) and Present Position(132).

LED(65)

Turn on or turn off the LED on Dynamixel.

Bit	Description
0(Default)	Turn OFF the LED
1	Turn ON the LED

Status Return Level(68)

This value decides how to return Status Packet when Dynamixel receives an Instruction Packet.

Value	Responding Instructions	Description
0	PING Instruction	Status Packet will not be returned for all Instructions
1	PING Instruction READ Instruction	Status Packet will be returned only for READ Instruction
2	All Instructions	Status Packet will be returned for all Instructions

NOTE : If the ID of Instruction Packet is set to Broad Cast ID(0xFE), Status Packet will not be returned for READ and WRITE Instructions regardless of Status Return Level. For more details, please refer to the Status Packet section for Protocol 1.0 or Protocol 2.0.

Registered Instruction(69)

Value	Description
0	REG_WRITE instruction is not received
1	REG_WRITE instruction is received

NOTE : If ACTION instruction is executed, the value will be changed to 0.

Hardware Error Status(70)

The Dynamixel can protect itself by detecting dangerous situations that could occur during the operation.
Each Bit is inclusively processed with the ‘OR’ logic, therefore, multiple options can be generated.
For instance, when ‘0x05’ (binary : 00000101) is defined in Shutdown(63), Dynamixel can detect both Input Voltage Error(binary : 00000001) and Overheating Error(binary : 00000100).
If those errors are detected, Torque Enable(64) is cleared to ‘0’ and the motor output becomes 0[%].
REBOOT is the only method to reset Torque Enable(64) to ‘1’(Torque ON) after the shutdown.
The followings are detectable situations.

Bit	Item	Description
Bit 7	-	Unused, Always ‘0’
Bit 6	-	Unused, Always ‘0’
Bit 5	Overload Error(default)	Detect persistent load that exceeds maximum output
Bit 4	Electrical Shock Error(default)	Detect electric shock on the circuit or insufficient power to operate the motor
Bit 3	Motor Encoder Error	Detect malfunction of the motor encoder
Bit 2	OverHeating Error(default)	Detect internal temperature exceeds the configured operating temperature
Bit 1	-	Unused, Always ‘0’
Bit 0	Input Voltage Error	Detect input voltage exceeds the configured operating voltage

NOTE : If Shutdown occurs, LED will flicker every second.(Firmware v41 or above)

Velocity PI Gain(76, 78)

These values indicate Gains of Velocity Control Mode. Gains of DYNAMIXEL’s internal controller can be calculated from Gains of the Control Table as shown below. Velocity P Gain of DYNAMIXEL’s internal controller is abbreviated to K_VP and that of the Control Table is abbreviated to K_VP_(TBL).

	Controller Gain	Conversion Equations	Range	Description
Velocity I Gain(76)	KVI	KVI = KVI(TBL) / 65,536	0 ~ 16,383	I Gain
Velocity P Gain(78)	KVP	KVP = KVP(TBL) / 128	0 ~ 16,383	P Gain

Below figure is a block diagram describing the velocity controller in Velocity Control Mode. When the instruction transmitted from the user is received by DYNAMIXEL, it takes following steps until driving the horn.

1. An Instruction from the user is transmitted via DYNAMIXEL bus, then registered to Goal Velocity(104).
2. Goal Velocity(104) is converted to desired velocity trajectory by Profile Acceleration(108).
3. The desired velocity trajectory is stored at Velocity Trajectory(136).
4. PI controller calculates PWM output for the motor based on the desired velocity trajectory.
5. Goal PWM(100) sets a limit on the calculated PWM output and decides the final PWM value.
6. The final PWM value is applied to the motor through an Inverter, and the horn of DYNAMIXEL is driven.
7. Results are stored at Present Position(132), Present Velocity(128), Present PWM(124) and Present Current(126).

NOTE : K_vA stands for Anti-windup Gain and ‘β’ is a conversion coefficient of position and velocity that cannot be modified by users. For more details about the PID controller, please refer to the PID Controller at wikipedia.

Position PID Gain(80, 82, 84), Feedforward 1st/2nd Gains(88, 90)

These Gains are used in Position Control Mode and Extended Position Control Mode. Gains of Dynamixel’s internal controller can be calculated from Gains of the Control Table as shown below. The constant in each equations include sampling time. Position P Gain of Dynamixel’s internal controller is abbreviated to K_PP and that of the Control Table is abbreviated to K_PP_(TBL).

	Controller Gain	Conversion Equations	Range	Description
Position D Gain(80)	KPD	KPD = KPD(TBL) / 16	0 ~ 16,383	D Gain
Position I Gain(82)	KPI	KPI = KPI(TBL) / 65,536	0 ~ 16,383	I Gain
Position P Gain(84)	KPP	KPP = KPP(TBL) / 128	0 ~ 16,383	P Gain
Feedforward 2nd Gain(88)	KFF2nd	KFF2nd(TBL) / 4	0 ~ 16,383	Feedforward Acceleration Gain
Feedforward 1st Gain(90)	KFF1st	KFF1st(TBL) / 4	0 ~ 16,383	Feedforward Velocity Gain

Below figure is a block diagram describing the position controller in Position Control Mode and Extended Position Control Mode. When the instruction from the user is received by Dynamixel, it takes following steps until driving the horn.

1. An Instruction from the user is transmitted via Dynamixel bus, then registered to Goal Position(116).
2. Goal Position(116) is converted to desired position trajectory and desired velocity trajectory by Profile Velocity(112) and Profile Acceleration(108).
3. The desired position trajectory and desired velocity trajectory is stored at Position Trajectory(140) and Velocity Trajectory(136) respectively.
4. Feedforward and PID controller calculate PWM output for the motor based on desired trajectories.
5. Goal PWM(100) sets a limit on the calculated PWM output and decides the final PWM value.
6. The final PWM value is applied to the motor through an Inverter, and the horn of Dynamixel is driven.
7. Results are stored at Present Position(132), Present Velocity(128), Present PWM(124) and Present Current(126).

NOTE : In case of PWM Control Mode, both PID controller and Feedforward controller are deactivated while Goal PWM(100) value is directly controlling the motor through an Inverter. In this manner, users can directly control the supplying voltage to the motor.

NOTE : K_a is an Anti-windup Gain that cannot be modified by users.

Below figure is a block diagram describing the current-based position controller in Current-based Position Control Mode. As Current-based Position Control Mode is quite similar to Position Control Mode, differences will be focused in the following steps. The differences are highlighted with a green marker in the block diagram as well.

1. Feedforward and PID controller calculates desired current based on desired trajectory.
2. Goal Current(102) decides the final desired current by setting a limit on the calculated desired current.
3. Current controller calculates PWM output for the motor based on the final desired current.
4. Goal PWM(100) sets a limit on the calculated PWM output and decides the final PWM value.
5. The final PWM value is applied to the motor through an Inverter, and the horn of DYNAMIXEL is driven.
6. Results are stored at Present Position(132), Present Velocity(128), Present PWM(124) and Present Current(126).

NOTE : K_a is an Anti-windup Gain that cannot be modified by users.
For more details about the PID controller and Feedforward controller, please refer to the PID Controller and Feed Forward.

Bus Watchdog(98)

Bus Watchdog (98) is available from firmware v38. It is a safety device (Fail-safe) that stops the DYNAMIXEL if the communication between the controller and DYNAMIXEL communication (RS485, TTL) is disconnected due to an unspecified error. Communication is defined as all the Instruction Packet in the DYNAMIXEL Protocol.

	Values	Description
Unit	20[ms]	-
Range	0	Deactivate Bus Watchdog Function, Clear Bus Watchdog Error
Range	1 ~ 127	Activate Bus Watchdog
Range	-1	Bus Watchdog Error Status

The Bus Watchdog function monitors the communication interval (time) between the controller and DYNAMIXEL when Torque Enable (64) is ‘1’. If the measured communication interval (time) is larger than Bus Watchdog (98), the DYNAMIXEL will stop. Bus Watchdog (98) will be changed to ‘-1’ (Bus Watchdog Error). If the Bus Watchdog Error screen appears, the Goal Value (Goal PWM(100), Goal Current(102), Goal Velocity(104), Goal Position(116)) will be changed to read-only-access. Therefore, when a new value is written to the Goal Value, a Range Error will be returned via the Status packet. If the value of Bus Watchdog (98) is changed to ‘0’, Bus Watchdog Error will be cleared.

NOTE : For details of Range Error, please refer to the protocol of the e-Manual.

The following are examples of the operation of the Bus Watchdog function.

1. After setting the operating mode (11) to speed control mode, change the Torque Enable (64) to ‘1’.
2. If ‘50’ is written in the Goal Velocity (104), the DYNAMIXEL will rotate in CCW direction.
3. Change the value of Bus Watchdog (98) to ‘100’ (2,000 [ms]). (Activate Bus Watchdog Function)
4. If no instruction packet is received for 2,000 [ms], the DYNAMIXEL will stop. When it stops, the Profile Acceleration (108) and Profile Velocity (112) are applied as ‘0’.
5. The value of Bus Watchdog (98) changes to ‘-1’ (Bus Watchdog Error). At this time, the access to the Goal Value will be changed to read-only.
6. If ‘150’ is written to the Goal Velocity (104), Range Error will be returned via Status Packet.
7. If the value of Bus Watchdog (98) is changed to ‘0’, Bus Watchdog Error will be cleared.
8. If “150” is written in the Goal Velocity (104), the DYNAMIXEL will rotate in CCW direction.

Goal PWM(100)

In case of PWM Control Mode, both PID controller and Feedforward controller are deactivated while Goal PWM(100) value is directly controlling the motor through an Inverter. In other control modes, this value is used to limit PWM value. This value cannot exceed PWM Limit(36). Please refer to the Gain section in order to see how Goal PWM(100) affects to different control modes.

Range	Description
-PWM Limit(36) ~ PWM Limit(36)	Initial Value of PWM Limit(36) : ‘885’

Goal Current(102)

In case of Torque Control Mode, Goal Current(102) can be used to set a desired current. This value sets a limit to current in Current-based Position Control mode. This value cannot exceed Current Limit(38).

Unit	Value Range
about 2.69[mA]	-Current Limit(38) ~ Current Limit(38)

NOTE : Applying high current to the motor for long period of time might damage the motor.

Goal Velocity(104)

In case of Velocity Control Mode, Goal Velocity(104) can be used to set a desired velocity. This value cannot exceed Velocity Limit(44). For now, Goal Velocity(104) is used for desired velocity, but this value is not used to limit the velocity.

Unit	Value Range
0.229 rpm	-Velocity Limit(44) ~ Velocity Limit(44)

NOTE : The maximum velocity and maximum torque of DYNAMIXEL is affected by supplying voltage.
Therefore, if supplying voltage changes, so does the maximum velocity. This manual complies with recommended supply voltage(12[V]).

NOTE : If Profile Acceleration(108) and Goal Velocity(104) are modified simultaneously, modified Profile Acceleration(108) will be used to process Goal Velocity(104).

Profile Acceleration(108)

If Velocity-based Profile is selected for Drive Mode(10), Profile Acceleration(108) sets acceleration of the Profile.
If Time-based Profile is selected for Drive Mode(10), Profile Acceleration(108) sets accelerating time of the Profile.
Profile Acceleration(108) is applied in all control mode except Current Control Mode.
Please refer to Profile Velocity(112) for more details.

Velocity-based Profile	Values	Description
Unit	214.577 [rev/min2]	Sets acceleration of the Profile
Range	0 ~ 32767	‘0’ stands for an infinite acceleration

Time-based Profile	Values	Description
Unit	1 [msec]	Sets accelerating time of the Profile
Range	0 ~ 32737	‘0’ stands for an infinite accelerating time(‘0 [msec]’). Profile Acceleration(108) will not exceed 50% of Profile Velocity(112) value.

Profile Velocity(112)

If Velocity-based Profile is selected for Drive Mode(10), Profile Velocity(112) sets the maximum velocity of the Profile.
If Time-based Profile is selected for Drive Mode(10), Profile Velocity(112) sets the time span for the Profile.
Profile Velocity(112) is applied only in Position Control Mode and Extended Position Control Mode.

NOTE: Velocity Control Mode only uses Profile Acceleration(108) without Profile Velocity(112).

Velocity-based Profile	Values	Description
Unit	0.229 [rev/min]	Sets velocity of the Profile
Range	0 ~ 32767	‘0’ stands for an infinite velocity

Time-based Profile	Values	Description
Unit	1 [msec]	Sets the time span for the Profile
Range	0 ~ 32737	‘0’ stands for an infinite velocity. Profile Acceleration(108) will not exceed 50% of Profile Velocity(112) value.

The Profile is an acceleration/deceleration control method to reduce vibration, noise and load of the motor by controlling dramatically changing velocity and acceleration.
It is also called Velocity Profile as it controls acceleration and deceleration based on velocity.
DYNAMIXEL provides 3 different types of Profile.
The following explains 3 Profiles.
Profiles are usually selected by a combination of Profile Velocity(112) and Profile Acceleration(108).

When given Goal Position(116), Dynamixel’s profile creates desired velocity trajectory based on present velocity(initial velocity of the Profile).
When Dynamixel receives updated desired position from a new Goal Position(116) while it is moving toward the previous Goal Position(116), velocity smoothly varies for the new desired velocity trajectory.
Maintaining velocity continuity while updating desired velocity trajectory is called Velocity Override.
For a simple calculation, let’s assume that the initial velocity of the Profile is ‘0’.
The following explains how Profile processes Goal Position(116) instruction in Position Control mode, Extended Position Control Mode, Current-based Position Control Mode.

1. An Instruction from the user is transmitted via Dynamixel bus, then registered to Goal Position(116) (If Velocity-based Profile is selected).
2. Acceleration time(t1) is calculated from Profile Velocity(112) and Profile Acceleration(108).
3. Types of Profile is decided based on Profile Velocity(112), Profile Acceleration(108) and total travel distance(ΔPos, the distance difference between desired position and present position).
4. Selected Profile type is stored at Moving Status(123).(Refer to the Moving Status(123))
5. Dynamixel is driven by the calculated desired trajectory from Profile.
6. desired velocity trajectory and desired position trajectory from Profile are stored at Velocity Trajectory(136) and Position Trajectory(140) respectively.

Condition	Types of Profile
VPRFL(112) = 0	Profile not used (Step Instruction)
(VPRFL(112) ≠ 0) & (APRF(108) = 0)	Rectangular Profile
(VPRFL(112) ≠ 0) & (APRF(108) ≠ 0)	Trapezoidal Profile

Goal Position(116)

Desired position can be set with Goal Position(116). From the front view of Dynamixels, CCW is an increasing direction whereas CW is a decreasing direction. The way to reaching Goal Position(116) is differ by 4 Profiles provided by Dynamixels. Please refer to the Profile Velocity(112) for more details.

Mode	Values	Description
Position Control Mode	Min Position Limit(52) ~ Max Position Limit(48)	Initial Value : 0 ~ 4,095
Extended Position Control Mode	-1,048,575 ~ 1,048,575	-256[rev] ~ 256[rev]
Current-based Position Control Mode	-1,048,575 ~ 1,048,575	-256[rev] ~ 256[rev]

Degree Conversion Constant	Description
0.088°/Value	1[rev] : 0 ~ 4,095

NOTE : Profile Velocity(112) and Profile Acceleration(108) are applied in below cases:
In Position Control Mode, Profile Velocity(112) and Profile Acceleration(108) are used to create a new profile when Goal Position(116) is updated.
In Velocity Control Mode, Profile Acceleration(108) is used to create a new profile when Goal Velocity(104) is updated.

Realtime Tick(120)

This value indicates Dynamixel’s time.

Unit	Value Range	Description
1 ms	0 ~ 32,767	The value resets to ‘0’ when it exceeds 32,767

Moving(122)

This value indicates whether Dynamixel is in motion or not.
If absolute value of Present Velocity(128) is greater than Moving Threshold(24), Moving(122) is set to ‘1’.
Otherwise, it will be cleared to ‘0’.
However, this value will always be set to ‘1’ regardless of Present Velocity(128) while Profile is in progress with Goal Position(116) instruction.

Value	Description
0	Movement is not detected
1	Movement is detected, or Profile is in progress(Goal Position(116) instruction is being processed)

Moving Status(123)

This value provides additional information about the movement. Following Error Bit(0x08) and In-Position Bit(0x01) only work with Position Control Mode, Extended Position Control Mode, Current-based Position Control Mode.

		Details	Description
Bit 7	0x80	-	Unused
Bit 6	0x40	-	Unused
Bit 5 ~ Bit 4	0x30	Profile Type(0x30) Profile Type(0x20) Profile Type(0x10) Profile Type(0x00)	Trapezoidal Velocity Profile Triangular Velocity Profile Rectangular Velocity Profile Profile is not used
Bit 3	0x08	Following Error	Dynamixel fails to reach desired position trajectory
Bit 2	0x04	-	Unused
Bit 1	0x02	Profile Ongoing	Profile is in progress with Goal Position(116) instruction
Bit 0	0x01	In-Position	Dynamixel is reached to desired position

NOTE : Triangular velocity profile is configured when Rectangular velocity profile cannot reach to the Profile Velocity(112).

Present PWM(124)

This value indicates current PWM. For more details, please refer to the Goal PWM(100).

Present Current(126)

This value indicates current Current. For more details, please refer to the Goal Current(102).

Present Velocity(128)

This value indicates current Velocity. For more details, please refer to the Goal Velocity(104).

Present Position(132)

This value indicates present Position. For more details, please refer to the Goal Position(116).

Velocity Trajectory(136)

This is a desired velocity trajectory created by Profile. Operating method can be changed based on control mode. For more details, please refer to the Profile Velocity(112).

1. Velocity Control Mode : When Profile reaches to the endpoint, Velocity Trajectory(136) becomes equal to Goal Velocity(104).
2. Position Control Mode, Extended Position Control Mode, Current-based Position Control Mode : Velocity Trajectory is used to create Position Trajectory(140). When Profile reaches to an endpoint, Velocity Trajectory(136) is cleared to ‘0’.

Position Trajectory(140)

This is a desired position trajectory created by Profile.
This value is only used in Position Control Mode, Extended Position Control Mode and Current-based Position Control Mode.
For more details, please refer to the Profile Velocity(112).

Present Input Voltage(144)

This value indicates present voltage that is being supplied. For more details, please refer to the Max/Min Voltage Limit(32, 34).

Present Temperature(146)

This value indicates internal temperature of Dynamixel. For more details, please refer to the Temperature Limit(31).

External Port Data 1,2,3

Through External Port Data, signal on the External Port can be read or data can be written on the External Port.
The External Port is not electrically insulated, therefore abide by the electrical specifications.
For more accurate measurement, use shielded cable or twisted cable.
The shorter the length, the better the result.

External Port Mode	Access	Details	Electrical Characteristics
Common	-	-	0 ~ 3.3[V], 0 ~ 5[mA] VESD(HBM) : 2[kV]
0(AI)	Read	Converts External Port signal to digital value External Data = signal x (4,095 / 3.3)	Resolution : 12[bit] (0 ~ 4,095)
1(DO_PP)	Write	0 : Set External Port output to 0[V] 1 : Set External Port output to 3.3[V]	Output High level(VOH) : 2.4 [V] (min) Output Low level(VOL) : 0.5 [V] (max)
2(DI_PU) 3 (DI_PD)	Read	0: External Port input is 0[V] 1 : External Port input is 3.3[V]	Input High level(VIH) : 2.3 [V] (min) Input Low level(VIL) : 1.0 [V] (max) Pull-Up/Down : 40 [kΩ] (typ)

※ VESD(HBM) : ESD(Electrostatic Discharge) Voltage(human body model)

Indirect Address, Indirect Data

Indirect Address and Indirect Data are useful when accessing two remote addresses in the Control Table as sequential addresses. Sequential addresses increase Instruction Packet efficiency. Addresses that can be defined as Indirect Address is limited to RAM area(Address 64 ~ 661). If specific address is allocated to Indirect Address, Indirect Address inherits features and properties of the Data from the specific Address. Property includes Size(Byte length), value range, and Access property(Read Only, Read/Write). For instance, allocating 65(Address of LED) to Indirect Address 1(168), Indirect Data 1(224) can perform exactly same as LED(65).

Example 1 Allocating Size 1 byte LED(65) to Indirect Data 1(224).

1. Indirect Address 1(168) : change the value to ‘65’ which is the address of LED.
2. Set Indirect Data 1(224) to ‘1’ : LED(65) also becomes ‘1’ and LED is turned on.
3. Set Indirect Data 1(224) to ‘0’ : LED(65) also becomes ‘0’ and LED is turned off.

Example 2 Allocating Size 4 byte Goal Position(116) to Indirect Data 2(225), 4 sequential bytes have to be allocated.

1. Indirect Address 2(170) : change the value to ‘116’ which is the first address of Goal Position.
2. Indirect Address 3(172) : change the value to ‘117’ which is the second address of Goal Position.
3. Indirect Address 4(174) : change the value to ‘118’ which is the third address of Goal Position.
4. Indirect Address 5(176) : change the value to ‘119’ which is the fourth address of Goal Position.
5. Set 4 byte value ‘1,024’ to Indirect Data 2 : Goal Position(116) also becomes ‘1024’ and Dynamixel moves.

Indirect Address Range	Description
64 ~ 661	EEPROM address can’t be assigned to Indirect Address

NOTE : In order to allocate Data in the Control Table longer than 2[byte] to Indirect Address, all address must be allocated to Indirect Address like the above Example 2.

NOTE : Indirect Address 29 ~ 56 and Indirect Data 29 ~ 56 can only be accessed with Protocol 2.0.

How to Assemble

Wiring through Back Case

Option Frame Assembly

Maintenance

Horn and Gear Replacement

The horn is installed on the front wheel gear serration of the DYNAMIXEL whereas the bearing set is installed on the back.

Installing the Horn

When installing horn, carefully match the align markings on the horn and the wheel gear serration.

Once alignment is properly done, gently push the center of the horn toward the actuator.

Gear Replacement

You may need to replace the internal gear set when gears are worn out or damaged. Please follow the gear replacement instruction video.

Reference

Compatibility Guide
Harness Compatibility

Quick Start

Prerequisites

• Power supply to DYNAMIXEL(12V SMPS / Controllers)
• PC with Windows or OSX
• Connection between PC and DYNAMIXEL (U2D2, USB2Dynamixel or Micro USB cable)

R+ Manager

In order to change settings of DYNAMIXEL, R+ Manager 1.0 or R+ Manager 2.0 must be installed on your system.
You can also use Dynamixel SDK or Dynamixel Workbench.

Connector Information

Item	TTL	RS-485	External Port	Dual Joint
Pinout	1 GND 2 VDD 3 DATA	1 GND 2 VDD 3 DATA+ 4 DATA-	1 GND 2 VDD 3 PORT 1 4 PORT 2 5 PORT 3	1 PWM1 2 PWM2 3 ENABLE
Diagram
Housing	JST EHR-03	JST EHR-04	MOLEX 51021-0500	MOLEX 51021-0300
PCB Header	JST B3B-EH-A	JST B4B-EH-A	MOLEX 53047-0510	MOLEX 53398-0371
Crimp Terminal	JST SEH-001T-P0.6	JST SEH-001T-P0.6	MOLEX 50079-8100	MOLEX 50058-8000
Wire Gauge	21 AWG	21 AWG	26 AWG	26 AWG

WARNING: Check the pinout! The pinout of Dynamixel can differ from the pinout of connector manufacturer.

Communication Circuit

To control the Dynamixel actuators, the main controller needs to convert its UART signals to the half duplex type. The recommended circuit diagram for this is shown below.

TTL Communication

RS-485 Communication

The power of Dynamixel is supplied via Pin1(-), Pin2(+).
(The above circuit is built into Dynamixel-only controller.)
In the above circuit diagram, the direction of data signal of TxD and RxD in the TTL Level is determined according to the level of DIRECTION 485 as follows:
In case of DIRECTION485 Level = High: The signal of TxD is output to D+ and D-
In case of DIRECTION485 Level = Low: The signal of D+ and D- is output to RxD

WARNING: Check the pinout! The pinout of Dynamixel can differ from the pinout of connector manufacturer.

Drawings

• Download X_540.pdf
• Download X-540.dwg
• Download dummy_X540_std.stp
• Download dummy_X540_idle.stp

Please also checkout ROBOTIS Download Center for software applications, 3D/2D CAD, and other useful resources!