DM-J4340P-2EC geared motor (Cross roller bearing)

Original user manual（Chinese）

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Date	Version	Changes
2023.11.16	V1.0	First version created

Disclaimer

Thank you for purchasing ™DAMIAO ™DM-J4340P-2EC geared motor (hereinafter referred to as "the motor"). Before using this product, please carefully read and follow this document and all safety guidelines provided by DAMIAO Technology. Failure to do so may cause harm to you and those around you, or damage to this product or other surrounding items.

By using this product, you acknowledge that you have carefully read this document, understand, acknowledge, and accept all the terms and contents of this document and all related documents concerning this product.

You promise to use this product only for legitimate purposes. You promise to assume full responsibility for the use of this product and any consequences that may arise. DAMIAO Technology shall not be liable for any damage, injury, or any legal liability caused directly or indirectly by the use of this product.

DAMIAO is a trademark of Shenzhen DAMIAO Technology Co., Ltd. Product names, brands, etc. Appearing in this document are trademarks of their respective companies. This product and manual are copyrighted by Shenzhen DAMIAO Technology Co. Ltd. Reproduction or reprinting without permission will be prohibited. The final interpretation right of this document and all related documents concerning this product belongs to Shenzhen DAMIAO Technology Co., Ltd.

Updates may be made without notice.

Warnings

1. Please strictly operate in specified environment and keep the motor under maximum rated temperature. Otherwise, permanent and irreversible damage may occur.
2. Prevent entering foreign objects into the rotor, as this will cause abnormal rotor operation.
3. Before use, please check that all components are intact. If any parts are missing, aged, or damaged, please stop using the motor.
4. Ensure correct wiring and the motor is installed correctly and securely.
5. Do not touch the rotor during use to avoid any accidents. The motor will generate heat when outputting high torque, please take precautions to avoid burns.
6. Please do not disassemble the motor. This will affect the motor's control accuracy and cause abnormal motor operation.

Features

1. Dual encoder equipped, single-turn absolute position output provide no loss of absolute position during power outages
2. Integrated motor and driver design, compact structure, and high integration
3. Visualized debugging and firmware upgrades supported by Damiao debugging tools
4. Readable motor speed, position, torque, and temperature information via CAN bus
5. Dual temperature protection
6. Supports trapezoidal acceleration and deceleration in position mode

Packing list

1. Motor(built in driver) x1
2. Power(with CAN communication terminals) connection cable: XT30(2+2)-F plug single end connection cable (100mm) ×1
3. Serial port signal cable for debugging: GH1.25 connector - 3pin(Different side, 300mm) ×1

Interface and wiring specifications

Connector name-Number	Interface mark	Description
Power connector-1 （with CAN connector）		Connect the power supply via the XT30(2+2)-F plug, with a rated voltage 24V to power the motor. By connecting to an external control device via the CAN communication terminal, it can receive CAN control commands and provide feedback on motor status information. The motor has two power connectors. Either can be connected and used individually, or multiple motors can be connected in series, which makes wiring much easier.
Power connector-2 （with CAN connector）
Debugging serial port-3		Connect to a PC by using the GH1.25 connector cable (-3 pin) and a USB to CAN debugging tool (or a USB to serial module). Use Damiao Technology debugging assistant to set motor parameters and upgrade firmware.

Motor dimension and installation

Refer the motor mounting hole dimensions and locations to install the motor into the corresponding equipment.

States of indicator lamp

Normal states	Static green	ERR bit is 1,Enable mode, working normally
	Static red	ERR bit is 0, Disable mode
Abnormal states	Blink red	This indicates a fault, and the corresponding fault type is as shown: 8------Over voltage 9------Under voltage A------Over current B------MOSFET Over temperature C------Coil over temperature D------Communication lost E------Overloaded You can check the feedback frame and figure out which fault has occurred via Damiao Technology debugging assistant interface.

Operating modes

MIT mode

The MIT mode is designed for compatible with the original MIT mode, allowing for seamless switching for flexibly setting the control range (P_MAX, V_MAX, T_MAX).

The driver converts the received CAN data into control variables, calculates the torque value, and uses it as the current setpoint for the current loop. The current loop then adjusts according to its regulation rules to ultimately achieve the given torque current. Its control block diagram is as follows:

Based on the MIT (Mutual Aspect Ratio) model, various control modes can be derived. For example, when kp=0 and kd is not 0, a given v_des will achieve uniform rotation. When kp=0 and kd=0, a given t_ff will achieve a given torque output.

Note: When controlling the position, kd cannot be set to 0. Otherwise it will cause the motor vibrate or go out of control.

Position speed mode

The position cascade mode employs a three-loop series control method. The position loop acts as the outermost loop, and its output serves the reference for the speed loop. The output of the speed loop serves the reference for the inner current loop, controlling the actual current output. The control block diagram is shown below:

p_des is the target position to be controlled, and v_des is the maximum absolute velocity value during the motion process.

Using the control parameters recommended by the debugging assistant during the position cascade mode, it can achieve good control accuracy and a relatively smooth control, but the response time is relatively long. In addition to v_des, configurable parameters include acceleration/deceleration settings. These parameters can compensate unexpected oscillations during control.

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

Speed mode

The speed mode allows the motor to turn continuously setting target speed. The control block diagram is shown below:

Note: The unit of v_des is rad/s, and type of the data is float. If you need to use the debugging assistant to automatically calculate parameters, you need to set the damping factor to a non-zero positive value. Typically, the value is between 2.0 and 10.0. Too small damping factor will cause oscillation and large overshoot, while too large damping factor will cause a long rise time. The recommended setting is 4.0.

Force position hybrid control mode

The force position hybrid control mode dynamically controls the output torque based on the position-speed mode control. Its control block diagram is as follows:

A current command saturation stage was added after the output command of the speed loop to limit the current loop's input to a given range.

Use

The control uses the CAN standard frame format with a fixed baud rate of 1 Mbps. It is divided into receive frames and feedback frames. Receive frames contain the received control data, used to command and control the motor. feedback frames contain the motor's status data sent to the upper-level controller. Depending on the selected motor mode, the receive frame format and frame IDs are different, but the feedback frame is the same across all modes.

Feedback frame

The feedback frame ID is set by the debugging assistant (Master ID), with a default value 0. It mainly provides motor's position, speed, and torque information, and its frame format is 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

ID represents controller's ID, It is come from CAN_ID's lower 8 bit.

• ERR

  It shows fault,The corresponding fault type is as shown:

  • 0------Disable
  • 1------Enable
  • 8------Over voltage
  • 9------Under voltage
  • A------Over current
  • B------MOSFET Overheat
  • C------Coil Overheat
  • D------Communication lost
  • E------Overloaded

• POS: Motor position

• VEL: Motor speed

• T: Motor output torque

• T_MOS: Average temperature of MOSFETS mounted on the driver (unit: degree)

• T_Rotor: Average temperature of Motor's coil（unit: degree）

Position, velocity, and torque are converted from floating-point data into signed fixed-point data using a linear mapping method. Position using 16 bit data and velocity and torque using 12 bit data.

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]

The frame ID is as same as the CAN_ID set by debugging assistant.

• p_des：Desired position
• v_des：Desired speed
• Kp：Proportional control ratio for position control
• Kd：Derivative control ration for speed control
• t_ff：Feed forward torque value

Each parameter conforms to the mapping method in the previous section. The numbers of p_des, v_des, and t_ff can be set by the debugging assistant.

The range of Kp is [0, 500], and the range of Kd is [0, 5].

Assignment: CAN number is only one level, with 8 characters, MIT's restraint command format: Position, Velocity, Kp, Kd, ​​Torque. Among them: Position 2 characters 16 bits, Velocity 12 bits, Kp 12 bits, Kd 12 bits

Control frame of Position speed mode

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

The frame ID is the set CAN ID value plus an offset of 0x100.

• p_des：Target position, floating-point type LSB first,MSB last (little endian).
• v_des：Target speed, floating-point type LSB first,MSB last (little endian).

The CAN ID for the command here is 0x100+ID. The target speed is the highest speed of trapezoidal acceleration, which is the speed value of the constant speed segment.

Speed mode control frame

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

The frame ID is the set CAN ID value plus an offset of 0x200.

• v_des：Target speed, floating-point type LSB first,MSB last (little endian).

The CAN ID for the command here is 0x200+ID.

Control frame of force position hybrid control mode

Control message is as follows:

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

• p_des
  • Target position given in rad, floating-point,LSB first, MSB last.
• v_des
  • Speed ​​limit value in rad/s, magnified by 100, Type is unsigned 16 bit, LSB first, MSB last, range is 0-10000, Exceeding 10000 will be limited to 10000, so the corresponding actual speed limit is 0~100rad/s.
• i_des *Torque current limit value, magnified 10000. Type is unsigned 16 bit, LSB first, MSB last. The range is 0-10000, exceeding 10000 will be limited to 10000. the corresponding actual current limit per-unit is 0-1.0 current per-unit value: actual current value divided by maximum current value, DM-J4340P-2EC maximum current 10.26A.

Read parameters

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

RID: Register addresses. see Appendix <Register List and Range>.

Reading succeeded, the data in the register will be returned with the following frame format:

Message ID	Property	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

The data is either floating-point data or unsigned integer, occupying 32 bits (4 bytes in total), with the LSB D4 and the MSB being D7, and so on.

Write parameters

Message ID	Property	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

As shown above, the RID will be returned after a successful write, and the frame format is the same as that sent.

Message ID	Property	D[0]	D[1]	D[2]	D[3]	D[4]	D[5]	D[6]	D[7]
MST_ID	STD	CANID_L	CANID_H	0x55	RID	Data

Data written to the register takes effect immediately, cannot be stored so will be lost after power off. Store parameters command needs to write all the modified parameters into the chip.

Save parameters

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

Upon successful writing, this message will sent:

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

Note:

1. Stored parameter is only applied inDisable mode.
2. All parameters will be retained at once when storing parameters.
3. This operation writes the parameters into the on-chip flash memory. Each operation takes 30ms maximum. please keep sufficient time of powered.
4. The flash memory has approximately 10,000 write/erase cycles. please do not send "store parameters" commands frequently.

Mode switching

It supports switching between multiple modes. The currently supported control modes are as follows:

Number	Mode
1	MIT
2	Pos speed
3	Speed
4	Force position hybrid control

The mode can be changed by modifying the value of the mode register (0x0A). When switching modes, the motor first clears the command value. This includes position, speed, and torque feedforward and KP,KD values ​​in MIT mode.

When switching from one mode to the position control mode, it is recommended to read the precise position first (the value of register 0x50) to prevent shock. And try to switch when the motor is at zero speed.

After the mode is changed, it will not be stored in flash memory and will be lost when power is off. After powered again, the control mode will be set to the mode last stored in flash memory.

Change the baud rate of CAN communication

The CAN communication baud rate can be modified by writing specific data to the baud rate register (address 0x23). Specific baud rate modification is supported. The currently supported baud rates are as follows:

Number	Baud rate
0	125K
1	200K
2	250K
3	500K
4	1M
5	2M
6	2.5M
7	3.2M
8	4M
9	5M

After successfully modifying the baud rate, the driver initially feeds back data at the original baud rate. And then communicates at the new baud rate. When powered-up, the motor first checks the stored baud rate. If it's greater than 5Mbps, it automatically defaults to 1Mbps. For baud rates greater than 1Mbps (excluding 1Mbps), it automatically switches to CAN FD function. If the baud rate is less than or equal to 1Mbps, it automatically switches to CAN 2.0B. Motors configured as CAN FD can still receive CAN 2.0B data frames, but they send feedback frames using CAN FD. Therefore, the upper-level controller will not receive feedback data, and the driver will continuously report errors. If a controller using CAN 2.0B has an incorrect ID setting, the baud rate can still be changed back using the baud rate modification command.

Using Damiao Debugging Assistant

Using the Damiao Technology USB to CAN debugging tool, connect the computer and the motor, and use the Damiao Technology assistant to set the motor parameters and upgrade the firmware.

The motor debugging serial port is connected to the PC via the GH1.25 connector cable -3pin. The CAN communication terminal in the motor power interface is connected to the USB to CAN debugging tool via the XT30 (2+2)-F connector cable. The motor parameters are set and firmware is upgraded using the Damiao Technology debugging assistant.

After connecting the motor's serial port, CAN port, and power interface, open the Damiao Technology Debugging Assistant on the computer, select the corresponding serial port device, and open the serial port. Then, supply power to the motor. the serial port will print information, with "Control Mode" indicating the current drive mode.

Characteristic parameters

Please use the motor appropriately according to the following parameters.

Type	Characteristic parameters	DM-J4340P-2EC（24V）	DM-J4340P-2EC（48V）
Motor parameters	Rated voltage	24V	48V
	Rated current	2.5A	2.5A
	Peak current	8A	8A
	Rated torque	9NM	9NM
	Peak torque	27NM	27NM
	Rated speed	36rpm	36rpm
	Maximum speed under no-load	52rpm	100rpm
Motor characteristic value	Reduction ratio	40:1	40:1
	Number of pole pairs	14	14
	Phase inductance	360μH	360μH
	Phase resistance	880mΩ	880mΩ
Structure and weight	Outer diameter	57mm	57mm
	Height	56.5mm	56.5mm
	Motor weight	375g Approx	375g Approx
Encoders	Encoder resolution	14 bit	14 bit
	Number of encoders	2	2
	Encoder type	Magnetic（single lap）	Magnetic（single lap）
Communication	Control interface	CAN@1Mbps
	Parameter adjust interface	UART@921600bps
Control and protection	Control mode	MIT mode
		Speed mode
		Position mode
		Force position hybrid control mode
	Protection	Driver overheat protection: The protection temperature is 120℃. If the temperature exceeds this limit, the motor will exit "Enable mode".
		Motor overheat protection. It should be set according to requirements of usage however recommended not to exceed 100℃. Over-temperature protection will cause the motor to exit "Enable mode".
		Motor overvoltage protection should be set according to usage requirements, but it is recommended not to exceed 32V. Overvoltage will exit "Enable mode".	Motor overvoltage protection should be set according to usage requirements, but it is recommended not to exceed 52V. Overvoltage will exit "Enable mode".
		Communication loss protection: If no CAN command is received within a set period, the system will automatically exit "Enable mode".
		Motor overcurrent protection: It should be set according to usage requirements, but it is recommended not to exceed 9.8A. Overcurrent will exit "Enable mode".
		Motor undervoltage protection: If the power supply voltage is lower than the set value, the "Enable mode" will be exited. It is recommended that the power supply voltage not be lower than 15V.	Motor undervoltage protection: If the power supply voltage is lower than the set value, the "Enable mode" will be exited. It is recommended that the power supply voltage not be lower than 15V.

Appendix Register List and Range

Address (HEX)	Address (DEC)	Variable	Description	R/W	Value range	Type
0x00	0	UV_Value	UV protection value	RW	(10.0,fmax]	float
0x01	1	KT_Value	Torque coefficient	RW	[0.0,fmax]	float
0x02	2	OT_Value	Over temperature value	RW	[80.0,200)	float
0x03	3	OC_Value	Over current value	RW	(0.0,1.0)	float
0x04	4	ACC	Acceleration ratio	RW	(0.0,fmax)	float
0x05	5	DEC	deceleration ratio	RW	[-fmax,0.0)	float
0x06	6	MAX_SPD	Maximum speed	RW	(0.0,fmax]	float
0x07	7	MST_ID	Feedback ID	RW	[0,0x7FF]	uint32
0x08	8	ESC_ID	Receive ID	RW	[0,0x7FF]	uint32
0x09	9	TIMEOUT	Timeout time	RW	[0,2^32-1]	uint32
0x0A	10	CTRL_MODE	Control mode	RW	[0,4]	uint32
0x0B	11	Damp	Motor damping factor	RO	/	float
0x0C	12	Inertia	Motor rotational inertia	RO	/	float
0x0D	13	hw_ver	Reserved	RO	/	uint32
0x0E	14	sw_ver	Software version	RO	/	uint32
0x0F	15	SN	Reserved	RO	/	uint32
0x10	16	NPP	Motor pole pairs number	RO	/	uint32
0x11	17	Rs	Motor phase resistance	RO	/	float
0x12	18	Ls	Motor phase inductance	RO	/	float
0x13	19	Flux	Motor flux linkage	RO	/	float
0x14	20	Gr	Gear reduction ratio	RO	/	float
0x15	21	PMAX	Location mapping range	RW	(0.0,fmax]	float
0x16	22	VMAX	Speed mapping range	RW	(0.0,fmax]	float
0x17	23	TMAX	Torque mapping range	RW	(0.0,fmax]	float
0x18	24	I_BW	Current loop control range	RW	[100.0,1.0e4]	float
0x19	25	KP_ASR	Speed loop Kp	RW	[0.0,fmax]	float
0x1A	26	KI_ASR	Speed 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	Over voltage protection	RW	TBD	float
0x1E	30	GREF	Gear torque efficiency	RW	(0.0,1.0]	float
0x1F	31	Deta	Speed loop damping cofficient	RW	[1.0,30.0]	float
0x20	32	V_BW	Velocity loop damping coefficient	RW	(0.0,500.0)	float
0x21	33	IQ_c1	Current loop enhancement factor	RW	[100.0,1.0e4]	float
0x22	34	VL_c1	Velocity loop enhancement factor	RW	(0.0,1.0e4]	float
0x23	35	can_br	CAN baud rate code	RW	[0,4]	uint32
0x24	36	sub_ver	Sub version number	RO	/	uint32
0x32	50	u_off	U phase bias	RO	/	float
0x33	51	v_off	V phase bias	RO	/	float
0x34	52	k1	Compensation value 1	RO	/	float
0x35	53	k2	Compensation value 2	RO	/	float
0x36	54	m_off	Angle offset	RO	/	float
0x37	55	dir	Direction	RO	/	float
0x50	80	p_m	Motor current position	RO	/	float
0x51	81	xout	Output shaft current position	RO	/	float

• RW：Read Write
• RO：Read Only