README.md

cansendcrc

Script for automatic CRC calculation for cansend. It will calculate proper CRC and execute cansend command with CRC applied.

Tested with Raspberry Pi 5, Waveshare RS485 CAN HAT, MKS SERVO42D CAN MB.

Installation

Download cansendsrc file or git clone this repository

sudo chmod +x cansendsrc

Usage

./cansendcrc <CAN_ID>#<data_bytes>

Where

<CAN_ID> is slave device ID

<data_bytes> are the actual bytes without CRC

Example

Command:

./cansendcrc 002#f300

Answer: Calculated CRC: F5 cansend can0 002#f300F5

Installation of Waveshare RS485 CAN HAT on Raspberry Pi 5

sudo apt update && sudo apt upgrade -y
sudo apt-get install can-utils -y
echo -e "dtparam=spi=on\ndtoverlay=mcp2515-can0,oscillator=12000000,interrupt=25,spimaxfrequency=2000000" | sudo tee -a /boot/firmware/config.txt
# check oscillator on  RS485 CAN HAT is 12.000
sudo reboot now
sudo ip link set can0 down
sudo ip link set can0 up type can bitrate 500000 #you need to set CanRate on the motor to 500k manually
wget https://github.com/syproduction/cansendcrc/raw/main/cansendcrc
sudo chmod +x cansendcrc

Commands for MKS SERVO42D CAN MB

Commands are without CRC since we dont need it with cansendcrc

CanID for the motor is 2, thats why there are 002 before #

Answers were received with candump can0

Table of Contents

• 30 Read the Encoder Value (Carry)
• 31 Read the Encoder Value (Addition)
• 30 32 Read the Real-Time Speed of the Motor (RPM)
• 33 Read the Number of Pulses Received
• 39 Read the Error of the Motor Shaft Angle
• 3A Read the EN Pins Status
• 3B Read the Go Back to Zero Status When Power On
• 3D Release the Motor Shaft Locked-Rotor Protection State
• 3E Read the Motor Shaft Protection State
• 80 00 Calibrate the Encoder (Same as the "Cal" option on screen)
• 82 Set the Work Mode (Same as the "Mode" option on screen)
• 83 Set the Current (Same as the "Ma" option on screen)
• 84 Set Subdivision (Same as the "MStep" option on screen)
• 85 Set the Active of the EN Pin
• 86 Set the Direction of Motor Rotation
• 87 Set Auto Turn Off the Screen Function
• 88 Set the Motor Shaft Locked-Rotor Protection Function
• 89 Set the Subdivision Interpolation Function
• 8A Set the CAN Bit Rate
• 8B Set the CAN ID
• 8C Set the Slave Respond
• 8D Set the Group ID
• 90 Set the Parameter of Home
• 91 Go Home
• 92 Set Current Axis to Zero
• 3F Restore the Default Parameter
• F1 Query the Motor Status
• F3 Enable/Disable the Motor
• F6 Run the Motor in Speed Mode
• F6 Stop the Motor in Speed Mode
• FF Save/Clear the Parameter in Speed Mode
• FD Run the Motor in Position Mode1
• FD Stop the Motor in Position Mode1
• F4 Run the Motor in Position Mode2
• FD Stop the Motor in Position Mode2
• F5 Run the Motor in Position Mode3
• F5 Stop the Motor in Position Mode3

---

30 Read the Encoder Value (Carry)

Command	Answer	Comment
002#30	can0 002 [8] 30 00 00 00 00 00 0B 3D
Where
	CAN ID: 002 (Identifier for the response)
	DLC: 8 (Number of data bytes in the response)
	Byte1: 30 (Indicates the response is for the 30 command)
	Bytes 2-5: 00 00 00 00 (Carry, 32-bit integer showing the number of full rotations)
	Bytes 6-7: 0B (Value, 16-bit integer showing the position within one rotation)	1° ≈ 11.38 Value
	Byte8: 3D (CRC, checksum for the response data)

31 Read the Encoder Value (Addition)

Command	Answer	Comment
002#31	can0 002 [8] 31 00 00 00 00 00 0C 3F
Where
	CAN ID: 002 (Identifier for the response)
	DLC: 8 (Number of data bytes in the response)
	Byte1: 31 (Indicates the response is for the 31 command)
	Bytes 2-6: 00 00 00 00 (Reserved or padding bytes)
	Byte7: 0C (Value, 16-bit integer, little-endian format)
	Byte8: 3F (CRC, checksum for the response data)

32 Read the Real-Time Speed of the Motor (RPM)

Command	Answer	Comment
002#32	can0 002 [4] 32 00 00 34
Where
	CAN ID: 002 (Identifier for the response)
	DLC: 4 (Number of data bytes in the response)
	Byte1: 32 (Indicates the response is for the 3032 command)
	Bytes2-3: 00 0C (Value, 16-bit integer in little-endian format)	Real-time speed of the motor in RPM.
	Byte4: 34 (CRC, checksum for the response data)

33 Read the Number of Pulses Received

Command	Answer	Comment
002#33	can0 002 [6] 33 00 00 00 00 35
Where
	CAN ID: 002 (Identifier for the response)
	DLC: 6 (Number of data bytes in the response)
	Byte1: 33 (Indicates the response is for the 33 command)
	Bytes2-5: 00 00 00 00 (Value, 32-bit integer in little-endian format)	The number of pulses received by the motor.
	Byte6: 35 (CRC, checksum for the response data)

39 Read the Error of the Motor Shaft Angle

The error is the difference between the angle you want to control minus the real-time angle of the motor, 0FFFF corresponds to 0360°.

Command	Answer	Comment
002#39	can0 002 [6] 39 00 00 00 1A 55
Where
	CAN ID: 002 (Identifier for the response)
	DLC: 6 (Number of data bytes in the response)
	Byte1: 39 (Indicates the response is for the 39 command)
	Bytes2-5: 00 00 00 1A (Value, 32-bit integer in little-endian format)
	Byte6: 55 (CRC, checksum for the response data)

Note:

• The error is calculated as the difference between the desired angle and the real-time angle of the motor.
• 0xFFFF (65536 in decimal) corresponds to 360°.
• For example, if the angle error is 1°, the returned error value is approximately 182 (65536/360 ≈ 182.444).

3A Read the EN Pins Status

Command	Answer	Comment
002#3A	can0 002 [3] 3A 01 3D
Where
	Byte1: 3A (Indicates the response is for the 3A command)
	Byte2: 01 (Value, 32-bit integer in little-endian format)	Enabled: Value = 1 , Disabled: Value = 0
	Byte6: 3D (CRC, checksum for the response data)

3B Read the Go Back to Zero Status When Power On

Command	Answer
002#3B	can0 002 [3] 3B 02 3F
Where
	Byte2: 02 (Status)
	status = 0 Going to zero
	status = 1 Go back to zero success
	status = 2 Go back to zero fail

3D Release the Motor Shaft Locked-Rotor Protection State

Command	Answer
002#3D	can0 002 [3] 3D 00 3F
Where
	Byte2: 00 (Status)
	status = 1 Release success
	status = 0 Release fail

3E Read the Motor Shaft Protection State

Command	Answer
002#3E	can0 002 [3] 3E 00 40
Where
	Byte2: 00 (Status)
	status = 1 Protected
	status = 0 Not protected

80 00 Calibrate the Encoder (Same as the "Cal" option on screen)

Command	Answer
002#8000	can0 002 [3] 80 00 82 can0 002 [3] 80 01 83
Where
	Byte2: 00, 01, 02 (Status)
	status = 0 Calibrating…
	status = 1 Calibrated success
	status = 2 Calibrating fail

Note: The motor must be unloaded

82 Set the Work Mode (Same as the "Mode" option on screen)

Command	Answer
002#8204	can0 002 [3] 82 01 85
Where
Byte2: 04 (Mode)	Byte2: 01 (Status)
	status = 1 Set success
	status = 0 Set fail

Mode	Name	Interface	Max RPM	Work Current	Encoder
0	CR_OPEN	Pulse	400	Fix, Ma	Without
1	CR_CLOSE	Pulse	1500	Fix, Ma	With
2	CR_vFOC	Pulse	3000	Adaptive, Max current = Ma	With
3	SR_OPEN	Serial	400	Fix, Ma	Without
4	SR_CLOSE	Serial	1500	Fix, Ma	With
5	SR_vFOC	Serial	3000	Adaptive, Max current = Ma	With

(Default: CR_vFOC)

83 Set the current （Same as the "Ma" option on screen）

Command	Answer
002#8300AA	can0 002 [3] 83 01 86
Where
Bytes2-3: 00 AA (Value 0000-0BB8, 16-bit hex integer)	Byte2: 01 (Status)
	status = 1 Set success
	status = 0 Set fail

Device Information:

• SERVO42D: Maximum Current = 3000mA
• SERVO57D: Maximum Current = 5200mA

84 Set subdivision （Same as the "MStep" option on screen）

Command	Answer
002#8410	can0 002 [3] 84 01 87
Where
Byte2 : 10 Value 00-ff (16 bit hex integer)	Byte2 : 01 Status
	status =1 Set success
	status =0 Set fail

85 Set the Active of the EN Pin

Command	Answer	Comment
002#8500	can0 002 [3] 85 01 88
Where
Byte2: 00		00 - Active Low (L), 01 - Active High (H), 02 - Active Always (Hold)
	Byte1: 85 (Indicates the response is for the 85 command)
	Byte2: 01 (Status)	Status = 1 Set success, Status = 0 Set fail
	Byte3: 88 (CRC, checksum for the response data)

86 Set the Direction of Motor Rotation

Command	Answer	Comment
002#8600	can0 002 [3] 86 01 89
Where
Byte2: 01 (Direction)		00 - CW (Clockwise), 01 - CCW (Counterclockwise)
	Byte2: 01 (Status)	Status = 1 Set success, Status = 0 Set fail

87 Set Auto Turn Off the Screen Function

Command	Answer	Comment
002#8700	can0 002 [3] 87 01 8A
Where
Byte2: 01 (Enable)		enable = 01 enabled, enable = 00 disabled
	Byte2: 01 (Status)	Status = 1 Set success, Status = 0 Set fail

If set to Enable, the screen will automatically turn off after about 15 seconds, and any button can wake up the screen again

88 Set the Motor Shaft Locked-Rotor Protection Function

Command	Answer	Comment
002#8800	can0 002 [3] 88 01 8B
Where
Byte2: 01 (Enable)		01 enabled protection, 00 disabled protection
	Byte2: 01 (Status)	Status = 1 Set success, Status = 0 Set fail

Note: You can release the protection status by pressing the Enter button or sending the serial command.

89 Set the Subdivision Interpolation Function

Command	Answer	Comment
002#8900	can0 002 [3] 89 01 8C
Where
Byte2: 00		00 - Disabled Interpolation Function, 01 - Enabled Interpolation Function
	Byte2: 01 (Status)	Status = 1 Set success, Status = 0 Set fail

8A Set the CAN Bit Rate

Command	Answer	Comment
002#8A00	can0 002 [3] 8A 01 8D
Where
Byte2: 00 (Bit Rate)		00 - 125K, 01 - 250K, 02 - 500K
	Byte2: 01 (Status)	Status = 1 Set success, Status = 0 Set fail

8B Set the CAN ID

Command	Answer	Comment
002#8B00	can0 002 [3] 8B 01 8E
Where
Byte2: 00 (CAN ID)		CAN ID = 00 to 7FF (0 is the broadcast address)
	Byte2: 01 (Status)	Status = 1 Set success, Status = 0 Set fail

Notes:

1. The new CAN ID will be displayed on the screen under the CanID option.
2. CAN ID 0 is used as the broadcast address.

8C Set the Slave Respond

Command	Answer	Comment
002#8C00	can0 002 [3] 8C 01 8F
Where
Byte2: 00 (Enable)		00 - Disable respond, 01 - Enable respond
	Byte2: 01 (Status)	Status = 1 Set success, Status = 0 Set fail

Note:

• If the response is disabled, you can still query the running status of the motor using the F1 command.

8D Set the Group ID

Command	Answer	Comment
002#8D00	can0 002 [3] 8D 01 90
Where
Byte2: 00 (Group ID)		01 - 7FF (Group ID range)
	Byte2: 01 (Status)	Status = 1 Set success, Status = 0 Set fail

Example Setup:

Motor	Broadcast ID	Slave ID	Group ID
Motor 1	0	1	0x50
Motor 2	0	2	0x50
Motor 3	0	3	0x50
Motor 4	0	4	0x51
Motor 5	0	5	0x51
Motor 6	0	6	0x51

Example Commands:

Command	Description
01 FD 01 2C 64 00 00 0C 80 1B	Motor 1 will rotate one turn.
00 FD 01 2C 64 00 00 0C 80 1A	Motors 1-6 will rotate one turn.
50 FD 01 2C 64 00 00 0C 80 6A	Motors 1-3 will rotate one turn.
51 FD 01 2C 64 00 00 0C 80 6B	Motors 4-6 will rotate one turn.

90 Set the Parameter of Home

Command	Answer	Comment
002#90000000	can0 002 [3] 90 00 92
Where
Byte2: 00 (homeTrig)		0 - Low, 1 - High
Byte3: 00 (homeDir)		0 - CW, 1 - CCW
Byte4: 00 (homeSpeed)		0~3000 RPM (Speed of going home)
	Byte2: 01 (Status)	0 - Set fail, 1 - Set success

91 Go Home

Command	Answer	Comment
002#91	can0 002 [3] 91 01 94
Where
	Byte2: 00 (Status)	0 - Go home fail, 1 - Go home start, 2 - Go home success

92 Set Current Axis to Zero

Command	Answer	Comment
002#92	can0 002 [3] 92 01 95
Where
	Byte2: 01 (Status)	0 - Set fail, 1 - Set success

3F Restore the Default Parameter

Command	Answer	Comment
002#3F	can0 002 [3] 3F 01 42
Where
	Byte2: 01 (Status)	0 - Restore fail, 1 - Restore success

Notes:

• After restoring the parameters, the system will reboot and you will need to calibrate the motor.
• Press the “Next” key, then power on the motor to restore the default parameters.

F1 Query the Motor Status

Command	Answer	Comment
002#F1	can0 01 [2] F1 01
Where
	Byte2: 01 (Status)	0 - Query fail, 1 - Motor stop, 2 - Motor speed up, 3 - Motor speed down, 4 - Motor full speed, 5 - Motor is homing

F3 Enable/Disable the Motor

Command	Answer	Comment
002#F301	can0 01 [3] F3 01 01
Where
Byte2: 01 (Enable)		00 - Disable, 01 - Enable
	Byte2: 01 (Status)	0 - Set fail, 1 - Set success

F6 Run the motor in speed mode

Command	Answer	Comment
002#F6014002	can0 01 [3] F6 01 01	the motor rotates forward at acc=2, speed=320RPM
002#F6814002	can0 01 [3] F6 81 02	the motor reverses at acc=2, speed=320RPM
Where
Byte2 higher bit: 01 (Direction)		0x - CW (Clockwise), 8x - CCW (Counter-Clockwise)
Byte2 lower+ Byte3: 01 40 (Speed)		Speed = 40 + (Lower 4 bits of Byte2) (Range: 0-3000 RPM)
Byte4: 02 (Acceleration)		0-255 (Acceleration value)
	Byte2: 01 (Status)	status = 1 run success, status = 0 run fail.

F6 Stop the Motor in Speed Mode

Command	Answer	Comment
002#F6000002	can0 01 [3] F6 00 02	Decelerate and stop the motor slowly with acc=2
002#F6000000	can0 01 [3] F6 00 00	Immediate stop with acc=0
Where
Byte2: 00 (Direction)		00 - No direction change, stops motor
Byte3: 00 (Speed)		00 - Speed is not relevant for stopping
Byte4: 02 (Acceleration)		0-255 (Acceleration value for deceleration)
	Byte2: 01 (Status)	status = 0 stop the motor fail, status = 1 start to stop the motor, status = 2 stop the motor success

Notes

• If the motor is running faster than 1000 RPM, it is not advisable to use an immediate stop as it may cause mechanical issues. Use deceleration (acc ≠ 0) for safer stopping.

FF Save/Clear the Parameter in Speed Mode

Command	Answer	Comment
002#FF00C8	can0 01 [3] FF C8 01	Save parameters
002#FF00CA	can0 01 [3] FF CA 01	Clear parameters
Where
Byte2: C8 (State)		C8 - Save parameters, CA - Clear parameters
	Byte2: 01 (Status)	status = 1 success, status = 0 fail

Notes

• After saving or clearing parameters, the motor can rotate clockwise or counterclockwise at a constant speed when powered on.

FD Run the Motor in Position Mode1

Command	Answer	Comment
002#FD01400200FA00	can0 002 [3] FD 00 FF	The motor rotates 20 times forward with acc=2, speed=320RPM (16 subdivisions)
002#FD81400200FA00	can0 002 [3] FD 00 FF	The motor rotates 20 times reverse with acc=2, speed=320RPM (16 subdivisions)
Where
Byte2 higher bit: 01 (Direction)		0x - CW (Clockwise), 8x - CCW (Counter-Clockwise)
Byte3 lower + Byte4: 40 02 (Speed)		Speed = 40 + (Lower 4 bits of Byte2) (Range: 0-3000 RPM)
Byte5-7: 00 FA 00 (Pulses)		Pulses = 0x00FA00 (Number of steps for the motor to run)
	Byte2 : 00 Status	status = 0 run fail, status = 1 run starting…., status = 2 run complete.

FD Stop the Motor in Position Mode1

Command	Answer	Comment
002#FD000004000000	can0 01 [3] FD 00 01	The motor stops with deceleration, acc=4
002#FD000000000000	can0 01 [3] FD 00 02	The motor stops immediately
Where
Byte2 higher bit: 00 (Direction)		Direction is not used for stopping
Byte3 lower + Byte4: 00 00 (Speed)		Speed is not used for stopping
Byte5-7: 04 00 00 (Acceleration)		acc = 4 for slow deceleration, acc = 0 for immediate stop
	Byte2 : 00 Status	status = 0 stop the motor fail, status = 1 stop the motor starting…, status = 2 stop the motor complete

F4 Run the Motor in Position Mode2

Command	Answer	Comment
002#F402580200400091	can0 01 [3] F4 01 01	The motor moves relative to the axis, speed = 600 RPM, acc = 2
002#F40258FF00C00009	can0 01 [3] F4 02 01	The motor moves relative to the axis in the reverse direction, speed = 600 RPM, acc = 2
Where
Byte2: 02 (Speed)		Speed = 02 * 100 + 58 (RPM, Range: 0-3000)
Byte3: 58 (Speed)		Speed = 58 + (Byte2 * 100) (RPM, Range: 0-3000)
Byte4: 02 (Acceleration)		0-255 (Acceleration value)
Byte5-7: 00 40 00 or FF C0 00 (Relative Axis)		Relative axis value (24-bit signed integer)
	Byte2: 01 (Status)	0 - Run fail, 1 - Run starting, 2 - Run complete

Notes

• The axis value can be read by command "31".
• In this mode, the axis error is about ±15.
• It is suggested to run with 64 subdivisions.

FD Stop the Motor in Position Mode2

Command	Answer	Comment
002#FD0000000400	can0 01 [3] FD 02 02	Stop the motor with deceleration, acc = 4
002#FD0000000000	can0 01 [3] FD 02 02	Stop the motor immediately
Where
Byte2: 00 (Direction)		0 - No change in direction (for stopping)
Byte3: 00 (Speed)		Speed = 00 (Not relevant for stop command)
Byte4: 00 (Acceleration)		0-255 (Acceleration value, used for deceleration)
Byte5-7: 00 00 00 or 00 00 00 (Pulses)		Pulses (Not relevant for stop command)
		02 - Deceleration and stop, FE - Immediate stop
	Byte2: 02 (Status)	0 - Stop fail, 1 - Stop starting, 2 - Stop complete

Notes

• The stop command can stop the motor slowly with deceleration (acc ≠ 0) or immediately (acc = 0).
• If the motor is rotating more than 1000 RPM, it is not recommended to stop the motor immediately.

F5 Run the Motor in Position Mode3

Command	Answer	Comment
002#F5025802004000	can0 01 [3] F5 01 01	The motor moves to absolute axis 0x4000, speed = 600 RPM, acc = 2
002#F5025802FFC000	can0 01 [3] F5 02 02	The motor moves to absolute axis -0x4000, speed = 600 RPM, acc = 2
Where
Byte2: 02 (Speed)		Speed = 02 * 100 + 58 (RPM, Range: 0-3000)
Byte3: 58 (Speed)		Speed = 58 + (Byte2 * 100) (RPM, Range: 0-3000)
Byte4: 02 (Acceleration)		0-255 (Acceleration value)
Byte5-7: 00 40 00 or FF C0 00 (Absolute Axis)		Absolute axis value (24-bit signed integer)
	Byte2: 01 (Status)	0 - Run fail, 1 - Run starting, 2 - Run complete

Notes

• The axis value can be read by command "31".
• In this mode, the axis error is about ±15.
• It is suggested to run with 64 subdivisions.

F5 Stop the Motor in Position Mode3

Command	Answer	Comment
002#F50000040000	can0 01 [3] F5 01 01	Stop the motor with deceleration, acc=4
002#F50000000000	can0 01 [3] F5 02 02	Stop the motor immediately, acc=0
Where
Byte2: 00 (Speed)		Not used in the stop command
Byte3: 00 (Acceleration)		0-255 (Deceleration value)
Byte4: 00 (Absolute Axis)		Not used in the stop command
Byte5-7: 00 00 00 (Unused)		Not used in the stop command
	Byte2: 01 (Status)	0 - Stop fail, 1 - Stop starting, 2 - Stop complete

Notes

• If the motor is rotating more than 1000 RPM, it is not a good idea to stop the motor immediately.
• The uplink frame provides status feedback on the stop command.