DM-J4340P-2EC V1.1 Motor Instruction Manual

DM-J4340P-2EC Motor User Guide

DAMIAO DM-J4340P-2EC Motor

DAMIAO DM-J4340P-2EC: 27N·m high-performance MIT-compatible brushless servo robotic joint motor. For quadrupeds, humanoids & exoskeletons. Motor for OpenArm.

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Safety Precautions

Operate the motor strictly within the specified environmental conditions and maximum winding temperature limits. Failure to do so may result in permanent damage.
Prevent foreign objects from entering the rotor. Otherwise, abnormal operation may occur.
Inspect all components before use. Do not operate the motor if any components are missing, wom, or damaged.
Ensure correct wiring and proper, secure motor installation.
Do not touch the rotating or energized parts during operation to avoid injury. High torque operation may generate heat. Avoid contact to prevent burns.
Do not disassemble the motor. Unauthorized disassembly may affect control accuracy or cause malfunction.

Motor Features

Dual encoders provide single-turn absolute position feedback at the output shaft, ensuring position information is retained even after power loss.
Integrated motor and driver design offers compact structure with high integration.
Supports PC-based configuration, monitoring, and firmware upgrades.
Provides real-time feedback of motor Velocity, position, torque, and temperature via CAN bus.
Features dual temperature protection mechanisms.
Supports trapezoidal acceleration and deceleration profiles in position mode.

Naming Conventions

For example：DM - J4340 X - 2EC VX.X (48V)

DM	(Brand)DAMIAO Technology
J	J：Joint Motor Series S：Separable Motor Series
43	Stator Diameter 35、43、60、62、80、100（mm）
40	Reduction Ratio 06、07、09、10、19、40、48
X -	Output Bearing Version -By default：Deep Groove Ball Bearing. -P：Crossed Roller Bearing. -L：Lite version (not related to bearing type).
2EC	Encoder -By default：single encoder. -1EC：Single encoder, CAN communication. -2EC：Dual encoders (single-turn absolute, output shaft),CAN communication. -1EE：Single encoder, EtherCAT communication. -2EE：Dual encoder (single-turn absolute, output shaft), EtherCAT communication.
VX.X	Motor Version
（48V）	Driver Rated Voltage -By default：24V drive voltage -48V ：48V drive voltage

Specifications

Please operate the motor within the specifications listed below.

Type	Characteristic Parameters	DM-J4340P-2EC V1.2（24V）	DM-J4340P-2EC V1.2（48V）
Motor parameters	Rated Voltage	24V	48V
	Rated Phase / Supply Current	4.11A/3.1A@24V	4.11A/1.8A@48V
	Peak Phase / Supply Current	19.85A/16.0A@24V	19.85A/11.2A@48V
	Rated Torque	14NM	14NM
	Peak Torque	40NM	40NM
	Rated speed	36rpm	36rpm
	Maximum No-Load Speed	56rpm	112rpm
Motor Characteristic Values	Reduction Ratio	1：40	1：40
	Pole Pairs	14	14
	Phase Inductance	290uH (@25℃)	290uH (@25℃)
	Phase Resistance	0.72mΩ (@25℃)	0.72mΩ (@25℃)
Structure and Weight	Outer Diameter	57mm	57mm
	Height	56.5mm	56.5mm
	Motor Weight	362g	362g
Encoder	Resolution (bits)	14 bit	14 bit
	Number of Encoders	2	2
	Type	Magnetic Encoder (Single-Turn)	Magnetic Encoder (Single-Turn)
Communication Method	Control Interface	CAN@1Mbps	CAN@1Mbps
	Configuration Interface	UART@921600bps	UART@921600bps
Control and Protection	Control Mode	MIT Mode	MIT Mode
		Velocity Mode	Velocity Mode
		Position Mode	Position Mode
		Force-Position Hybrid Mode	Force-Position Hybrid Mode
	Protection	Drive over-temperature protection: shutdown at 120° C; the motor exits Enable Mode when triggered.	Drive over-temperature protection: shutdown at 120° C; the motor exits Enable Mode when triggered.
		Motor over-temperature protection (configurable, recommended ≤ 100° C); the motor exits Enable Mode when triggered.	Motor over-temperature protection (configurable, recommended ≤ 100° C); the motor exits Enable Mode when triggered.
		Over-voltage protection(configurable, recommended ≤ 32V); exits Enable Mode when triggered.	Over-voltage protection(configurable, recommended ≤ 60V); exits Enable Mode when triggered.
		Communication Loss Protection: the motor exits Enable Mode if no CAN command is received within the specified timeout period.	Communication Loss Protection: the motor exits Enable Mode if no CAN command is received within the specified timeout period.
		Over-current protection (configurable, recommended ≤ 9.8A); exits Enable Mode when triggered.	Over-current protection (configurable, recommended ≤ 9.8A); exits Enable Mode when triggered.
		Under-voltage protection: the motor exits Enable Mode if supply voltage falls below the threshold (recommended ≥ 15V).	Under-voltage protection: the motor exits Enable Mode if supply voltage falls below the threshold (recommended ≥ 15V).

Operating Voltage

The operating voltage range for the 24V motor driver is 24V–28V, with a minimum operating voltage of 20V and a maximum of 28V.

For the 48V motor driver, the operating voltage range is 24V–48V, with a minimum operating voltage of 20V and a maximum of 58V.Hot-plugging is recommended to be avoided when the voltage exceeds 36V.

Maximum Phase Current

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Correction: The baud rate in the communication settings in the PC software shown in the screenshot below has been updated to 921600.

The maximum phase current of the driver can be obtained from the startup serial output:

The maximum phase current percentage can be limited by setting a percentage in the configuration tool. The default value is 0.8 (i.e., 80% of the measurable maximum current). It is recommended that this value not exceed 98%.

Maximum Rotational Speed

The maximum rotational speed is limited by multiple factors, including the power supply voltage (VBUS), rotor flux linkage (ψf), and gear ratio (GR). An upper limit can typically be calculated using the following formula:

$V_{MAX}(rad/s) = 0.57735 * \frac{V_{BUS}}{N_{pp} \times GR \times \psi_f}(rad/s)$

where VBUS is the supply voltage, Npp is the number of pole pairs, and ψf is the rotor flux linkage.

Torque Constant

The torque constant of the motor can be considered constant within its rated range. With a gearbox, it can be calculated using the following formula:

$K_{t} = 1.5 * N_{pp} * \psi_f * GR * GREF$

Where Npp is the number of pole pairs, ψf is the rotor flux linkage, GR is the gear ratio, and GREF is the gearbox torque transmission coefficient.

Torque–Speed (T–N) Curve

For the 24V version, at a constant speed of 36 rpm and room temperature of 25°C, the measured performance curve is as follows:

For the 48V version, at a constant speed of 36 rpm and room temperature of 25°C, the measured performance curve is as follows:

Packing List

Motor (with integrated driver) ×1
Power cable (with CAN interface) : XT30(2+2)-F connector, single-ended(100mm)×1
Debug serial cable: GH1.25 3-pin cable (reverse-side connector, 300mm) ×1

Interface & Pin Description

Interface / Pin No.	Instruction
Power Interface-1(with CAN interface)	1. Connect the power supply via the XT30(2+2)-F cable. The rated voltage is 24 V. 2. Connect external controller via the CAN communication interface to receive CAN control commands and transmit motor status feedback. 3. The motor features two power interfaces. Either interface can be used independently , or multiple motors can be daisy-chained for convenient wiring.
Power Interface-2(with CAN interface)	1. Connect the power supply via the XT30(2+2)-F cable. The rated voltage is 24 V. 2. Connect external controller via the CAN communication interface to receive CAN control commands and transmit motor status feedback. 3. The motor features two power interfaces. Either interface can be used independently , or multiple motors can be daisy-chained for convenient wiring.

Interface / Pin No.	Instruction
Debug Serial Interface(Port 3)	Connect to a PC via the GH1.25 3-pin cable using a USB-to-CAN adapter (or USB-to serial module) for parameters configuration and firmware upgrades.

Motor Dimensions and Mounting

Please install the motor onto the target equipment according to the motor mounting hole dimensions and layout.

LED Status

Normal Status	Solid Green	Enable Mode (ERR = 1), normal operation
	Solid Red	Disable Mode (ERR = 0)（Default state after power-on）
Fault Status	Flashing Red	Fault codes and fault conditions: 3 – Output shaft calibration error; 4 – Sensor output error; 5 – Motor encoder calibration error; 8 – Over-voltage; 9 – Under-voltage; A – Over-current; B – MOS over-temperature; C – Motor winding over-temperature; D – Communication loss; E – Overload; Fault conditions can be identified via the feedback frames or displayed in the the Damiao configuration software.

Operating Modes

MIT Mode

The MIT mode is compatible with the standard MIT control method, enabling seamless switching while allowing flexible configuration of control limits (P_MAX, V_MAX, T_MAX).

CAN commands are converted into torque values. The torque is then used as the reference for current control. See block diagram below.

Based on the MIT model, various control strategies can be derived. For instance, when kp=0 and kd ≠ 0, a constant rotational speed can be achieved by setting v_des. When kp=0 and kd=0, a torque output is applied directly by setting t_ff (feedforward torque).

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Note: When controlling position, kd must not be set to zero, as this may cause motor oscillation or even loss of control.

Position-Velocity Mode

This mode uses three control loops: position, velocity, and current(torque). The position loop sets the target for the velocity loop. The velocity loop then sets the target for the current loop. See block diagram below.

p_des represents the target position, while v_des limits the maximum absolute velocity during motion.

When tuned using recommended parameters from the configuration tool, this mode provides high accuracy and smooth motion, at the cost of slower response time.

In addition to v_des, acceleration and deceleration can also be configured. If additional oscillations occur, increasing acceleration/deceleration may help stabilize the system.

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Note: The units of p_des and v_des are rad and rad/s respectively, and both are of type float. The damping factor must be set to a non-zero positive value.Refer to the notes for velocity mode.

Velocity Mode

This mode keeps the motor running at the target velocity. See block diagram below.

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Note: The unit of v_des is rad/s and its data type is float. To use the automatic parameter calculation function of the debugging assistant, the damping factor must be set to a positive non-zero number. Typically, its value ranges from 2.0 to 10.0. A damping factor that is too small will cause velocity oscillations and large overshoot, while a damping factor that is too large will result in a long rise time. The recommended setting value is 4.0.

Force-Position Hybrid Mode

The force-position hybrid control mode is based on position-velocity control, with additional torque adjustment. Allows control of both position and output torque at the same time. See block diagram below.

A current command saturation stage is added after the velocity loop output command. This limits the current loop reference within the specified range.

Mode Switching

Mode switching can be configured via the host computer using the serial port. Simply select the desired mode and click "Write Parameters". After successful configuration using this method, the motor will automatically reset, and the mode will be stored inside the motor driver without being lost after power cycling.

Additionally, mode switching can also be performed via the CAN interface by modifying the content of the mode register. For details, refer to the "Mode Switching" section in the next chapter.

When using the CAN method, the motor will not reset, but the following five variables will be cleared to zero:

Position command value
Velocity command value
Torque command value (MIT mode)
kp (MIT mode)
kd (MIT mode)

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Note:If the"Save Parameters" command is not issued, the mode will not be stored. It will be lost after power loss and will load the last saved mode upon power-up.

CAN communication

After calibration, parameter identification, and parameter configuration are completed, the motor is ready for operation.

Control is performed using CAN standard frames (STD). The default baud rate is 1 Mbps, which can be modified via commands. Refer to the "CAN Baud Rate" section for details.

Frame Types:

CAN communication is divided into two types:

Command Frames

Frames received by the driver, used to send control commands to the motor.

Feedback Frames

Frames transmitted by the driver to the upper-level controller, containing motor status data.

Feedback Mechanism:

Feedback operates in a request-response manner. When the driver receives a CAN frame whose ID matches the configured motor CAN ID:

The lower 8 bits are used for validation.
The upper 3 bits are ignored.

Once a match is detected, the driver will transmit the current motor status to the CAN bus.

Frame Format:

The command frame format and frame ID vary depending on the selected control mode. The feedback frame format remains the same across all control modes.

CAN Baud Rate Configuration

The CAN baud rate can be configured in two ways:

Configuration via Serial Interface,.

The baud rate can be set through the host PC software via the serial interface.

Select the desired baud rate.
Click "Write Parameters" to apply.

After the setting is successfully written:

The motor will automatically reboot.
The baud rate will be stored in the driver.
The setting will persist after power cycling.

Configuration via CAN Interface The baud rate can also be modified via the CAN interface by writing to the corresponding baud rate register. See "CAN Baud Rate" in this chapter for details.

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Note: When modifying the baud rate via CAN, the operation may fail if multiple devices are present on the bus.

Use this method with caution. It is strongly recommended to configure the baud rate before connecting multiple devices.

Feedback Frame

The feedback frame ID is set via the configuration tool (Master ID), with a default value of 0. It primarily reports the motor position, velocity, and torque with the frame format defined as follows:

Feedback Message	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
MST_ID	ID\|ERR<<4	POS[15:8]	POS[7:0]	VEL[11:4]	VEL[3:0] \| T[11:8]	T[7:0]	T_MOS	T_Rotor

Where:

ID: Controller ID, using the lower 8 bits of CAN_ID
ERR : Status code, with the following meanings

0 – Disabled（Default state after power-on）

1 – Enabled

8 — Over-voltage

9 — Under-voltage

A — Over-current

B — MOSFET over-temperature

C — Motor coil over-temperature

D — Communication loss

E — Overload

POS : Motor position
VEL : Motor velocity
T : Motor torque
T_MOS : Average MOSFET temperature on the driver (℃ )
T_Rotor : Average motor coil temperature (℃ )

Position, velocity, and torque are are converted from floating-point data to signed fixed-point data using a linear mapping:

Position: 16-bit signed fixed-point representation.
Velocity: 12-bit signed fixed-point representation.
Torque: 12-bit signed fixed-point representation.

Control Frame in MIT Mode

Control Message	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
ID	p_des [15:8]	p_des [7:0]	v_des [11:4]	v_des[3:0] \| Kp[11:8]	Kp [7:0]	Kd [11:4]	Kd[3:0] \| t_ff[11:8]	t_ff[7:0]

Frame ID: Equals the configured CAN ID
p_des: Desired position
v_des: Desired velocity
Kp: Position proportional gain
Kd: Position derivative gain
T_ff: Feedforward torque

All parameter follows the mapping rules described in the previous section. The ranges for p_des, v_des, and t_ff can be configured via the configuration tool. Kp range: [0,500], Kd range: [0,5].

A standard CAN frame contains 8 bytes. In MIT mode, the control command packs Position, Velocity,Kp, Kd, and Torque into these 8 bytes:

Position: 16 bits (2 bytes)
Velocity: 12 bits
Kp: 12 bits
Kd: 12 bits

Control Frame in Position-Velocity Mode

Control Message	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0x100+ID	p_des	p_des	p_des	p_des	v_des	v_des	v_des	v_des

Frame ID: equals the configured CAN ID plus an offset of 0x100.
p_des: Desired position, float type, little-endian (low byte first, high byte last).
v_des: Desired velocity, float type, little-endian (low byte first, high byte last).

The CAN ID used to send commands here is 0x100 + ID. The velocity command represents the maximum velocity during trapezoidal acceleration, i.e., the constant velocity segment.

Control Frame in Velocity Mode

Control Message	D[0]	D[1]	D[2]	D[3]
0x200+ID	v_des	v_des	v_des	v_des

Frame ID: equals the configured CAN ID plus an offset of 0x200.
v_des: Desired velocity, float type, little-endian (low byte first, high byte last).

The CAN ID used to send commands here is 0x200 + ID.

Control Frame in Force-Position Hybrid Mode

Control Message	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0x300+ID	p_de	p_de	p_de	p_de	v_des	v_des	i_des	i_des

P_des: Desired position, in radians, float type, little-endian (low byte first, high byte last).
V_des: Velocity limit, in rad/s, scaled by 100, unsigned 16-bit, little-endian (low byte first, high byte last). Valid range: 0-10000. Values exceeding 10000 are capped at 10000, corresponding to an actual velocity limit range of 0-100 rad/s.
I_des: Torque current limit (per-unit), scaled by 10000, unsigned 16-bit type, little-endian (low byte first, high byte last). Valid range: 0-10000. Values exceeding 10000 are capped at 10000, corresponding to an actual current limit amplitude of 0-1.0.
Per-unit current: Actual current divided by the maximum phase current.

Enable

After power-up self-test, an "Enable" command must be sent to allow motor control. The "Enable" frame is a control frame, with the frame ID as described above. The data payload is identical across all modes as follows:

D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFC

Disable

The default power-on state of the motor is "Disable." In this state, the three-phase terminal voltages are identical, each being a 50% modulation of the power supply voltage. The "Disable" frame is a control frame, with the frame ID as described above. The data payload is defined as follows:

D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFD

Set Zero Position

The "Set Zero Position" frame is a control frame. This command sets the current output shaft position as the zero reference and resets the position command value to 0. The frame ID follows the definition above, and the data payload is defined as follows:

D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFE

Clear Faults

When faults such as overheating, sending a "Clear" can be sent to reset the fault state. The "Clear" frame is a control frame. The frame ID follows the definition above, and the data payload is defined as follows:

D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFB

Read parameters

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]
0x7FF	STD	CANID_L	CANID_H	0x33	RID

RID represents the register address; refer to the "Register Map" section for details in this manual.

Upon successful read, the value of the register is returned. The frame format is as follows:

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
MST_ID	STD	CANID_L	CANID_H	0x33	RID	data	data	data	data

The data is either a floating-point value or an unsigned integer, occupying 32 bits (4 bytes) in total.

The least significant bit is D4, and the most significant bit is D7. The same convention applies below.

Write parameters

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0x7FF	STD	CANID_L	CANID_H	0x55	RID	data	data	data	data

RID is defined as above. Upon successful write, the written value is returned. The frame format is identical to the transmitted frame.

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
MST_ID	STD	CANID_L	CANID_H	0x33	RID	data	data	data	data

Writing register data takes effect immediately but are not stored; They will be lost upon power-off unless a "Save Parameters" command is issued to store them in internal memory

Save parameters

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]
0x7FF	STD	CANID_L	CANID_H	0xAA	0x01

Upon successful execution, the return frame format is:

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]
MST_ID	STD	CANID_L	CANID_H	0xAA	0x01

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【Note】:

The "Save Parameters" command is only effective in Disabled Mode.
All parameters are stored simultaneously during this operation.
This operation writes parameters to the on-chip flash memory. The maximum execution time is 30ms; please allow sufficient time.
The flash memory supports approximately 10,000 erase/write cycles. Avoid frequent execution of the "Save Parameters" command.

Mode Switching

Multiple control modes are supported and can be switched as follows:

Code/ID	Mode
1	MIT
2	Position-Velocity
3	Velocity
4	Force-Position Hybrid Control

The mode can be changed by modifying the mode register (0x0A). During switching, the motor resets all command values to zero, including position, velocity, and torque feed-forward, KP, and KD in MIT mode.

When switching to a position control mode, to avoid impact, it is recommended to first read the precise position (value in register 0x50) and perform the switch when the motor is at zero speed whenever possible.

Mode changes are not saved to flash memory and will be lost after power-off. Upon restart, the motor loads the last mode stored in flash.

CAN Baud Rate Configuration

By writing specific value to the baud rate register (address 0x23), the current CAN communication baud rate can be modified. Supported baud rates are listed below:

Code/ID	Baud Rate
0	125K
1	200K
2	250K
3	500K
4	1M
5	2M
6	2.5M
7	3.2M
8	4M
9	5M

Baud Rate Switching Behavior:

After a successful update, the driver first transmits feedback using the original baud rate and then switch to communication using the new baud rate.

Baud Rate Handling at Power-Up:

At power-up, the driver determines the communication mode based on the stored baud rate.

If the stored baud rate exceeds 5Mbps, the baud rate is reset to 1Mbps by default.
If the baud rate is greater than 1 Mbps (excluding 1 Mbps), the driver operates in CAN FD mode.
If the baud rate is ≤ 1 Mbps, the driver operates in CAN 2.0B mode.

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CAN FD Compatibility Note: A motor configured in CAN FD mode can still receive CAN 2.0B data frames. However, feedback frames are transmitted using CAN FD. As a result, if the upper-level controller only supports CAN 2.0B, it will not receive feedback data, the driver may continuously report communication errors.

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Recovery Note: For controllers operating in CAN 2.0B mode, even if the CAN ID is incorrectly configured, the baud rate can still be restored by sending a baud rate configuration command.

Register Map

Address(HEX)	Address(DEC)	Variable	Description	R/W	Range	Type
0x00	0	UV_Value	Undervoltage Threshold	RW	(10.0,fmax]	float
0x01	1	KT_Value	Torque Constant	RW	[0.0,fmax]	float
0x02	2	OT_Value	Over-temperature Threshold	RW	[80.0,200)	float
0x03	3	OC_Value	Overcurrent Threshold	RW	(0.0,1.0)	float
0x04	4	ACC	Acceleration	RW	(0.0,fmax)	float
0x05	5	DEC	Deceleration	RW	[-fmax,0.0)	float
0x06	6	MAX_SPD	Max Velocity	RW	(0.0,fmax]	float
0x07	7	MST_ID	Master ID	RW	[0,0x7FF]	uint32
0x08	8	ESC_ID	Command CAN ID	RW	[0,0x7FF]	uint32
0x09	9	TIMEOUT	Timeout Threshold	RW	[0,2^32-1]	uint32
0x0A	10	CTRL_MODE	Control Mode	RW	[0,4]	uint32
0x0B	11	Damp	Viscous Damping	RO	/	float
0x0C	12	Inertia	Rotor Inertia	RO	/	float
0x0D	13	hw_ver	Reserved	RO	/	uint32
0x0E	14	sw_ver	Firmware Version	RO	/	uint32
0x0F	15	SN	Reservd	RO	/	uint32
0x10	16	NPP	Number of Pole Pairs	RO	/	uint32
0x11	17	Rs	Phase Resistance	RO	/	float
0x12	18	Ls	Phase Inductance	RO	/	float
0x13	19	Flux	Flux Linkage	RO	/	float
0x14	20	Gr	Gear Reduction Ratio	RO	/	float
0x15	21	PMAX	Position Mapping Range	RW	(0.0,fmax]	float
0x16	22	VMAX	Velocity Mapping Range	RW	(0.0,fmax]	float
0x17	23	TMAX	Torque Mapping Range	RW	(0.0,fmax]	float
0x18	24	I_BW	Current-loop Bandwidth	RW	[100.0,1.0e4]	float
0x19	25	KP_ASR	Velocity Loop Kp	RW	[0.0,fmax]	float
0x1A	26	KI_ASR	Velocity Loop Ki	RW	[0.0,fmax]	float
0x1B	27	KP_APR	Position Loop Kp	RW	[0.0,fmax]	float
0x1C	28	KI_APR	Position Loop Ki	RW	[0.0,fmax]	float
0x1D	29	OV_Value	Overvoltage Threshold	RW	TBD	float
0x1E	30	GREF	Gear Torque Efficiency	RW	(0.0,1.0]	float
0x1F	31	Deta	Velocity Loop Damping Coefficient	RW	[1.0,30.0]	float
0x20	32	V_BW	Velocity Loop Filter Bandwidth	RW	(0.0,500.0)	float
0x21	33	IQ_c1	Iq Gain	RW	[100.0, 1.0e4]	float
0x22	34	VL_c1	Velocity Loop Gain Factor	RW	(0.0,1.0e4]	float
0x23	35	can_br	CAN Baud Rate	RW	[0,4]	uint32
0x24	36	sub_ver	Sub-version	RO	/	uint32
0x25	37	Boot_ver	Boot Version	RO	/	uint32
0x37	55	dir	Direction	RO	/	float
0x38	56	m_off	Motor-side Angle Offset	RO	/	float
0x3B	59	Imax	Driver Current Limit	RO	/	float
0x3C	60	VBus	Bus Voltage	RO	/	float
0x3D	61	Tpcb	PCB Temperature	RO	/	float
0x3E	62	Tmtr	Motor Temperature	RO	/	float
0x3F	63	Iu_off	Phase U Current Offset	RO	/	float
0x40	64	Iv_off	Phase V Current Offset	RO	/	float
0x41	65	Iw_off	Phase W Current Offset	RO	/	float
0x50	80	p_m	Motor Position	RO	/	float
0x51	81	xout	Output Shaft Position	RO	/	float

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Note:

RW: Read/Write.
RO: Read-only.
Motor output shaft position is calculated form the rotor position, in radians (rad)
Output shaft position refers is measured directly by the output shaft encoder, in radians (rad).

Host Computer Guide

DAMIAO Host Computer User Manual

DAMIAO DM-J4340P-2EC Motor

DAMIAO DM-J4340P-2EC: 27N·m high-performance MIT-compatible brushless servo robotic joint motor. For quadrupeds, humanoids & exoskeletons. Motor for OpenArm.

aifitlab.com

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DM-J4340P-2EC Motor User Guide

DAMIAO DM-J4340P-2EC Motor

DAMIAO DM-J4340P-2EC: 27N·m high-performance MIT-compatible brushless servo robotic joint motor. For quadrupeds, humanoids & exoskeletons. Motor for OpenArm.

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Safety Precautions

Operate the motor strictly within the specified environmental conditions and maximum winding temperature limits. Failure to do so may result in permanent damage.
Prevent foreign objects from entering the rotor. Otherwise, abnormal operation may occur.
Inspect all components before use. Do not operate the motor if any components are missing, wom, or damaged.
Ensure correct wiring and proper, secure motor installation.
Do not touch the rotating or energized parts during operation to avoid injury. High torque operation may generate heat. Avoid contact to prevent burns.
Do not disassemble the motor. Unauthorized disassembly may affect control accuracy or cause malfunction.

Motor Features

Dual encoders provide single-turn absolute position feedback at the output shaft, ensuring position information is retained even after power loss.
Integrated motor and driver design offers compact structure with high integration.
Supports PC-based configuration, monitoring, and firmware upgrades.
Provides real-time feedback of motor Velocity, position, torque, and temperature via CAN bus.
Features dual temperature protection mechanisms.
Supports trapezoidal acceleration and deceleration profiles in position mode.

Naming Conventions

For example：DM - J4340 X - 2EC VX.X (48V)

DM	(Brand)DAMIAO Technology
J	J：Joint Motor Series S：Separable Motor Series
43	Stator Diameter 35、43、60、62、80、100（mm）
40	Reduction Ratio 06、07、09、10、19、40、48
X -	Output Bearing Version -By default：Deep Groove Ball Bearing. -P：Crossed Roller Bearing. -L：Lite version (not related to bearing type).
2EC	Encoder -By default：single encoder. -1EC：Single encoder, CAN communication. -2EC：Dual encoders (single-turn absolute, output shaft),CAN communication. -1EE：Single encoder, EtherCAT communication. -2EE：Dual encoder (single-turn absolute, output shaft), EtherCAT communication.
VX.X	Motor Version
（48V）	Driver Rated Voltage -By default：24V drive voltage -48V ：48V drive voltage

Specifications

Please operate the motor within the specifications listed below.

Type	Characteristic Parameters	DM-J4340P-2EC V1.2（24V）	DM-J4340P-2EC V1.2（48V）
Motor parameters	Rated Voltage	24V	48V
	Rated Phase / Supply Current	4.11A/3.1A@24V	4.11A/1.8A@48V
	Peak Phase / Supply Current	19.85A/16.0A@24V	19.85A/11.2A@48V
	Rated Torque	14NM	14NM
	Peak Torque	40NM	40NM
	Rated speed	36rpm	36rpm
	Maximum No-Load Speed	56rpm	112rpm
Motor Characteristic Values	Reduction Ratio	1：40	1：40
	Pole Pairs	14	14
	Phase Inductance	290uH (@25℃)	290uH (@25℃)
	Phase Resistance	0.72mΩ (@25℃)	0.72mΩ (@25℃)
Structure and Weight	Outer Diameter	57mm	57mm
	Height	56.5mm	56.5mm
	Motor Weight	362g	362g
Encoder	Resolution (bits)	14 bit	14 bit
	Number of Encoders	2	2
	Type	Magnetic Encoder (Single-Turn)	Magnetic Encoder (Single-Turn)
Communication Method	Control Interface	CAN@1Mbps	CAN@1Mbps
	Configuration Interface	UART@921600bps	UART@921600bps
Control and Protection	Control Mode	MIT Mode	MIT Mode
		Velocity Mode	Velocity Mode
		Position Mode	Position Mode
		Force-Position Hybrid Mode	Force-Position Hybrid Mode
	Protection	Drive over-temperature protection: shutdown at 120° C; the motor exits Enable Mode when triggered.	Drive over-temperature protection: shutdown at 120° C; the motor exits Enable Mode when triggered.
		Motor over-temperature protection (configurable, recommended ≤ 100° C); the motor exits Enable Mode when triggered.	Motor over-temperature protection (configurable, recommended ≤ 100° C); the motor exits Enable Mode when triggered.
		Over-voltage protection(configurable, recommended ≤ 32V); exits Enable Mode when triggered.	Over-voltage protection(configurable, recommended ≤ 60V); exits Enable Mode when triggered.
		Communication Loss Protection: the motor exits Enable Mode if no CAN command is received within the specified timeout period.	Communication Loss Protection: the motor exits Enable Mode if no CAN command is received within the specified timeout period.
		Over-current protection (configurable, recommended ≤ 9.8A); exits Enable Mode when triggered.	Over-current protection (configurable, recommended ≤ 9.8A); exits Enable Mode when triggered.
		Under-voltage protection: the motor exits Enable Mode if supply voltage falls below the threshold (recommended ≥ 15V).	Under-voltage protection: the motor exits Enable Mode if supply voltage falls below the threshold (recommended ≥ 15V).

Operating Voltage

The operating voltage range for the 24V motor driver is 24V–28V, with a minimum operating voltage of 20V and a maximum of 28V.

Maximum Phase Current

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Correction: The baud rate in the communication settings in the PC software shown in the screenshot below has been updated to 921600.

The maximum phase current of the driver can be obtained from the startup serial output:

Maximum Rotational Speed

$V_{MAX}(rad/s) = 0.57735 * \frac{V_{BUS}}{N_{pp} \times GR \times \psi_f}(rad/s)$

where VBUS is the supply voltage, Npp is the number of pole pairs, and ψf is the rotor flux linkage.

Torque Constant

The torque constant of the motor can be considered constant within its rated range. With a gearbox, it can be calculated using the following formula:

$K_{t} = 1.5 * N_{pp} * \psi_f * GR * GREF$

Where Npp is the number of pole pairs, ψf is the rotor flux linkage, GR is the gear ratio, and GREF is the gearbox torque transmission coefficient.

Torque–Speed (T–N) Curve

For the 24V version, at a constant speed of 36 rpm and room temperature of 25°C, the measured performance curve is as follows:

For the 48V version, at a constant speed of 36 rpm and room temperature of 25°C, the measured performance curve is as follows:

Packing List

Motor (with integrated driver) ×1
Power cable (with CAN interface) : XT30(2+2)-F connector, single-ended(100mm)×1
Debug serial cable: GH1.25 3-pin cable (reverse-side connector, 300mm) ×1

Interface & Pin Description

Interface / Pin No.	Instruction
Power Interface-1(with CAN interface)	1. Connect the power supply via the XT30(2+2)-F cable. The rated voltage is 24 V. 2. Connect external controller via the CAN communication interface to receive CAN control commands and transmit motor status feedback. 3. The motor features two power interfaces. Either interface can be used independently , or multiple motors can be daisy-chained for convenient wiring.
Power Interface-2(with CAN interface)	1. Connect the power supply via the XT30(2+2)-F cable. The rated voltage is 24 V. 2. Connect external controller via the CAN communication interface to receive CAN control commands and transmit motor status feedback. 3. The motor features two power interfaces. Either interface can be used independently , or multiple motors can be daisy-chained for convenient wiring.

Interface / Pin No.	Instruction
Debug Serial Interface(Port 3)	Connect to a PC via the GH1.25 3-pin cable using a USB-to-CAN adapter (or USB-to serial module) for parameters configuration and firmware upgrades.

Motor Dimensions and Mounting

Please install the motor onto the target equipment according to the motor mounting hole dimensions and layout.

LED Status

Normal Status	Solid Green	Enable Mode (ERR = 1), normal operation
	Solid Red	Disable Mode (ERR = 0)（Default state after power-on）
Fault Status	Flashing Red	Fault codes and fault conditions: 3 – Output shaft calibration error; 4 – Sensor output error; 5 – Motor encoder calibration error; 8 – Over-voltage; 9 – Under-voltage; A – Over-current; B – MOS over-temperature; C – Motor winding over-temperature; D – Communication loss; E – Overload; Fault conditions can be identified via the feedback frames or displayed in the the Damiao configuration software.

Operating Modes

MIT Mode

The MIT mode is compatible with the standard MIT control method, enabling seamless switching while allowing flexible configuration of control limits (P_MAX, V_MAX, T_MAX).

CAN commands are converted into torque values. The torque is then used as the reference for current control. See block diagram below.

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Note: When controlling position, kd must not be set to zero, as this may cause motor oscillation or even loss of control.

Position-Velocity Mode

p_des represents the target position, while v_des limits the maximum absolute velocity during motion.

When tuned using recommended parameters from the configuration tool, this mode provides high accuracy and smooth motion, at the cost of slower response time.

In addition to v_des, acceleration and deceleration can also be configured. If additional oscillations occur, increasing acceleration/deceleration may help stabilize the system.

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Note: The units of p_des and v_des are rad and rad/s respectively, and both are of type float. The damping factor must be set to a non-zero positive value.Refer to the notes for velocity mode.

Velocity Mode

This mode keeps the motor running at the target velocity. See block diagram below.

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Force-Position Hybrid Mode

A current command saturation stage is added after the velocity loop output command. This limits the current loop reference within the specified range.

Mode Switching

Additionally, mode switching can also be performed via the CAN interface by modifying the content of the mode register. For details, refer to the "Mode Switching" section in the next chapter.

When using the CAN method, the motor will not reset, but the following five variables will be cleared to zero:

Position command value
Velocity command value
Torque command value (MIT mode)
kp (MIT mode)
kd (MIT mode)

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Note:If the"Save Parameters" command is not issued, the mode will not be stored. It will be lost after power loss and will load the last saved mode upon power-up.

CAN communication

After calibration, parameter identification, and parameter configuration are completed, the motor is ready for operation.

Control is performed using CAN standard frames (STD). The default baud rate is 1 Mbps, which can be modified via commands. Refer to the "CAN Baud Rate" section for details.

Frame Types:

CAN communication is divided into two types:

Command Frames

Frames received by the driver, used to send control commands to the motor.

Feedback Frames

Frames transmitted by the driver to the upper-level controller, containing motor status data.

Feedback Mechanism:

Feedback operates in a request-response manner. When the driver receives a CAN frame whose ID matches the configured motor CAN ID:

The lower 8 bits are used for validation.
The upper 3 bits are ignored.

Once a match is detected, the driver will transmit the current motor status to the CAN bus.

Frame Format:

The command frame format and frame ID vary depending on the selected control mode. The feedback frame format remains the same across all control modes.

CAN Baud Rate Configuration

The CAN baud rate can be configured in two ways:

Configuration via Serial Interface,.

The baud rate can be set through the host PC software via the serial interface.

Select the desired baud rate.
Click "Write Parameters" to apply.

After the setting is successfully written:

The motor will automatically reboot.
The baud rate will be stored in the driver.
The setting will persist after power cycling.

Configuration via CAN Interface The baud rate can also be modified via the CAN interface by writing to the corresponding baud rate register. See "CAN Baud Rate" in this chapter for details.

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Note: When modifying the baud rate via CAN, the operation may fail if multiple devices are present on the bus.

Use this method with caution. It is strongly recommended to configure the baud rate before connecting multiple devices.

Feedback Frame

The feedback frame ID is set via the configuration tool (Master ID), with a default value of 0. It primarily reports the motor position, velocity, and torque with the frame format defined as follows:

Feedback Message	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
MST_ID	ID\|ERR<<4	POS[15:8]	POS[7:0]	VEL[11:4]	VEL[3:0] \| T[11:8]	T[7:0]	T_MOS	T_Rotor

Where:

ID: Controller ID, using the lower 8 bits of CAN_ID
ERR : Status code, with the following meanings

0 – Disabled（Default state after power-on）

1 – Enabled

8 — Over-voltage

9 — Under-voltage

A — Over-current

B — MOSFET over-temperature

C — Motor coil over-temperature

D — Communication loss

E — Overload

POS : Motor position
VEL : Motor velocity
T : Motor torque
T_MOS : Average MOSFET temperature on the driver (℃ )
T_Rotor : Average motor coil temperature (℃ )

Position, velocity, and torque are are converted from floating-point data to signed fixed-point data using a linear mapping:

Position: 16-bit signed fixed-point representation.
Velocity: 12-bit signed fixed-point representation.
Torque: 12-bit signed fixed-point representation.

Control Frame in MIT Mode

Control Message	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
ID	p_des [15:8]	p_des [7:0]	v_des [11:4]	v_des[3:0] \| Kp[11:8]	Kp [7:0]	Kd [11:4]	Kd[3:0] \| t_ff[11:8]	t_ff[7:0]

Frame ID: Equals the configured CAN ID
p_des: Desired position
v_des: Desired velocity
Kp: Position proportional gain
Kd: Position derivative gain
T_ff: Feedforward torque

All parameter follows the mapping rules described in the previous section. The ranges for p_des, v_des, and t_ff can be configured via the configuration tool. Kp range: [0,500], Kd range: [0,5].

A standard CAN frame contains 8 bytes. In MIT mode, the control command packs Position, Velocity,Kp, Kd, and Torque into these 8 bytes:

Position: 16 bits (2 bytes)
Velocity: 12 bits
Kp: 12 bits
Kd: 12 bits

Control Frame in Position-Velocity Mode

Control Message	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0x100+ID	p_des	p_des	p_des	p_des	v_des	v_des	v_des	v_des

Frame ID: equals the configured CAN ID plus an offset of 0x100.
p_des: Desired position, float type, little-endian (low byte first, high byte last).
v_des: Desired velocity, float type, little-endian (low byte first, high byte last).

The CAN ID used to send commands here is 0x100 + ID. The velocity command represents the maximum velocity during trapezoidal acceleration, i.e., the constant velocity segment.

Control Frame in Velocity Mode

Control Message	D[0]	D[1]	D[2]	D[3]
0x200+ID	v_des	v_des	v_des	v_des

Frame ID: equals the configured CAN ID plus an offset of 0x200.
v_des: Desired velocity, float type, little-endian (low byte first, high byte last).

The CAN ID used to send commands here is 0x200 + ID.

Control Frame in Force-Position Hybrid Mode

Control Message	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0x300+ID	p_de	p_de	p_de	p_de	v_des	v_des	i_des	i_des

P_des: Desired position, in radians, float type, little-endian (low byte first, high byte last).
V_des: Velocity limit, in rad/s, scaled by 100, unsigned 16-bit, little-endian (low byte first, high byte last). Valid range: 0-10000. Values exceeding 10000 are capped at 10000, corresponding to an actual velocity limit range of 0-100 rad/s.
I_des: Torque current limit (per-unit), scaled by 10000, unsigned 16-bit type, little-endian (low byte first, high byte last). Valid range: 0-10000. Values exceeding 10000 are capped at 10000, corresponding to an actual current limit amplitude of 0-1.0.
Per-unit current: Actual current divided by the maximum phase current.

Enable

D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFC

Disable

D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFD

Set Zero Position

D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFE

Clear Faults

D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFF	0xFB

Read parameters

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]
0x7FF	STD	CANID_L	CANID_H	0x33	RID

RID represents the register address; refer to the "Register Map" section for details in this manual.

Upon successful read, the value of the register is returned. The frame format is as follows:

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
MST_ID	STD	CANID_L	CANID_H	0x33	RID	data	data	data	data

The data is either a floating-point value or an unsigned integer, occupying 32 bits (4 bytes) in total.

The least significant bit is D4, and the most significant bit is D7. The same convention applies below.

Write parameters

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
0x7FF	STD	CANID_L	CANID_H	0x55	RID	data	data	data	data

RID is defined as above. Upon successful write, the written value is returned. The frame format is identical to the transmitted frame.

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
MST_ID	STD	CANID_L	CANID_H	0x33	RID	data	data	data	data

Writing register data takes effect immediately but are not stored; They will be lost upon power-off unless a "Save Parameters" command is issued to store them in internal memory

Save parameters

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]
0x7FF	STD	CANID_L	CANID_H	0xAA	0x01

Upon successful execution, the return frame format is:

Message ID	Attribute	D[0]	D[1]	D[2]	D[3]
MST_ID	STD	CANID_L	CANID_H	0xAA	0x01

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【Note】:

The "Save Parameters" command is only effective in Disabled Mode.
All parameters are stored simultaneously during this operation.
This operation writes parameters to the on-chip flash memory. The maximum execution time is 30ms; please allow sufficient time.
The flash memory supports approximately 10,000 erase/write cycles. Avoid frequent execution of the "Save Parameters" command.

Mode Switching

Multiple control modes are supported and can be switched as follows:

Code/ID	Mode
1	MIT
2	Position-Velocity
3	Velocity
4	Force-Position Hybrid Control

Mode changes are not saved to flash memory and will be lost after power-off. Upon restart, the motor loads the last mode stored in flash.

CAN Baud Rate Configuration

By writing specific value to the baud rate register (address 0x23), the current CAN communication baud rate can be modified. Supported baud rates are listed below:

Code/ID	Baud Rate
0	125K
1	200K
2	250K
3	500K
4	1M
5	2M
6	2.5M
7	3.2M
8	4M
9	5M

Baud Rate Switching Behavior:

After a successful update, the driver first transmits feedback using the original baud rate and then switch to communication using the new baud rate.

Baud Rate Handling at Power-Up:

At power-up, the driver determines the communication mode based on the stored baud rate.

If the stored baud rate exceeds 5Mbps, the baud rate is reset to 1Mbps by default.
If the baud rate is greater than 1 Mbps (excluding 1 Mbps), the driver operates in CAN FD mode.
If the baud rate is ≤ 1 Mbps, the driver operates in CAN 2.0B mode.

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Recovery Note: For controllers operating in CAN 2.0B mode, even if the CAN ID is incorrectly configured, the baud rate can still be restored by sending a baud rate configuration command.

Register Map

Address(HEX)	Address(DEC)	Variable	Description	R/W	Range	Type
0x00	0	UV_Value	Undervoltage Threshold	RW	(10.0,fmax]	float
0x01	1	KT_Value	Torque Constant	RW	[0.0,fmax]	float
0x02	2	OT_Value	Over-temperature Threshold	RW	[80.0,200)	float
0x03	3	OC_Value	Overcurrent Threshold	RW	(0.0,1.0)	float
0x04	4	ACC	Acceleration	RW	(0.0,fmax)	float
0x05	5	DEC	Deceleration	RW	[-fmax,0.0)	float
0x06	6	MAX_SPD	Max Velocity	RW	(0.0,fmax]	float
0x07	7	MST_ID	Master ID	RW	[0,0x7FF]	uint32
0x08	8	ESC_ID	Command CAN ID	RW	[0,0x7FF]	uint32
0x09	9	TIMEOUT	Timeout Threshold	RW	[0,2^32-1]	uint32
0x0A	10	CTRL_MODE	Control Mode	RW	[0,4]	uint32
0x0B	11	Damp	Viscous Damping	RO	/	float
0x0C	12	Inertia	Rotor Inertia	RO	/	float
0x0D	13	hw_ver	Reserved	RO	/	uint32
0x0E	14	sw_ver	Firmware Version	RO	/	uint32
0x0F	15	SN	Reservd	RO	/	uint32
0x10	16	NPP	Number of Pole Pairs	RO	/	uint32
0x11	17	Rs	Phase Resistance	RO	/	float
0x12	18	Ls	Phase Inductance	RO	/	float
0x13	19	Flux	Flux Linkage	RO	/	float
0x14	20	Gr	Gear Reduction Ratio	RO	/	float
0x15	21	PMAX	Position Mapping Range	RW	(0.0,fmax]	float
0x16	22	VMAX	Velocity Mapping Range	RW	(0.0,fmax]	float
0x17	23	TMAX	Torque Mapping Range	RW	(0.0,fmax]	float
0x18	24	I_BW	Current-loop Bandwidth	RW	[100.0,1.0e4]	float
0x19	25	KP_ASR	Velocity Loop Kp	RW	[0.0,fmax]	float
0x1A	26	KI_ASR	Velocity Loop Ki	RW	[0.0,fmax]	float
0x1B	27	KP_APR	Position Loop Kp	RW	[0.0,fmax]	float
0x1C	28	KI_APR	Position Loop Ki	RW	[0.0,fmax]	float
0x1D	29	OV_Value	Overvoltage Threshold	RW	TBD	float
0x1E	30	GREF	Gear Torque Efficiency	RW	(0.0,1.0]	float
0x1F	31	Deta	Velocity Loop Damping Coefficient	RW	[1.0,30.0]	float
0x20	32	V_BW	Velocity Loop Filter Bandwidth	RW	(0.0,500.0)	float
0x21	33	IQ_c1	Iq Gain	RW	[100.0, 1.0e4]	float
0x22	34	VL_c1	Velocity Loop Gain Factor	RW	(0.0,1.0e4]	float
0x23	35	can_br	CAN Baud Rate	RW	[0,4]	uint32
0x24	36	sub_ver	Sub-version	RO	/	uint32
0x25	37	Boot_ver	Boot Version	RO	/	uint32
0x37	55	dir	Direction	RO	/	float
0x38	56	m_off	Motor-side Angle Offset	RO	/	float
0x3B	59	Imax	Driver Current Limit	RO	/	float
0x3C	60	VBus	Bus Voltage	RO	/	float
0x3D	61	Tpcb	PCB Temperature	RO	/	float
0x3E	62	Tmtr	Motor Temperature	RO	/	float
0x3F	63	Iu_off	Phase U Current Offset	RO	/	float
0x40	64	Iv_off	Phase V Current Offset	RO	/	float
0x41	65	Iw_off	Phase W Current Offset	RO	/	float
0x50	80	p_m	Motor Position	RO	/	float
0x51	81	xout	Output Shaft Position	RO	/	float

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Note:

RW: Read/Write.
RO: Read-only.
Motor output shaft position is calculated form the rotor position, in radians (rad)
Output shaft position refers is measured directly by the output shaft encoder, in radians (rad).

Host Computer Guide

DAMIAO Host Computer User Manual

DAMIAO DM-J4340P-2EC Motor

DAMIAO DM-J4340P-2EC: 27N·m high-performance MIT-compatible brushless servo robotic joint motor. For quadrupeds, humanoids & exoskeletons. Motor for OpenArm.

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