FEETECH UAVCAN Servo – Memory Table Analysis

Magnetic Encoder UAVCAN Servo

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1. Communication Protocol

The servo uses the UAVCAN communication protocol. The factory default CAN baud rate is 1 Mbps. The configurable baud rate range is 20 Kbps to 1 Mbps. The communication address, CAN baud rate, and node ID can be configured via upper computer software.

2. UAVCAN Command Examples

The following commands use CAN 2.0B standard. Default motor NODE_ID is 100 (0x64).

Single-motor position command: 1807DB01 (Frame ID): 00 64 05 D5 (Data)

Level: 18

Frame type: 07DB (2011)

Frame source ID: 01

Frame data: 00 64 05 (channel 00, position data 0564)

Frame tail: D5

Multi-motor position command:

1807DC01 (Frame ID): 8E 82 64 05 00 00 00 97 (Data) 1807DC01 (Frame ID): 00 00 00 00 00 00 00 37 (Data) 1807DC01 (Frame ID): 00 00 00 00 00 00 00 17 (Data) 1807DC01 (Frame ID): 00 00 00 00 00 00 00 37 (Data) 1807DC01 (Frame ID): 00 00 00 00 00 00 00 17 (Data) 1807DC01 (Frame ID): 00 00 00 77 (Data)

Level: 18

Frame type: 07DC (2012)

Frame source ID: 01

CRC check code: 8E 82

Frame data: 64 05 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 (cmd[0]=0564, cmd[1]=0000, cmd[2]=0000 … cmd[17]=0000)

Frame tail: 97 / 37 / 17 / 37 / 17 / 77

Automatic feedback reporting command:

1807DD64 (Frame ID): A1 04 00 CC 0C CD 0C 80 (Data) 1807DD64 (Frame ID): 45 00 00 00 2A 00 00 60 (Data)

Level: 18

Frame type: 07DD (2013)

Frame source ID: 64

CRC check code: A1 04

Frame data:

00 CC 0C CD 0C 45 00 00 00 2A 00 00 (Servo_ID: 00, POS_CMD: 0CCC, POS_SENSOR: 0CCD, VOLTAGE: 0045, CURRENT: 0000, PCB_Temp: 2A, MOTOR_Temp: 00, StatusInfo: 00)

Frame tail: 80 / 60

Node status command: 18015564 (Frame ID): 50 03 00 00 00 00 00 D0 (Data)

Level: 18

Frame type: 0155 (341)

Frame source ID: 64

Frame data: 50 03 00 00 00 00 00 (uptime_sec: 00000350, health: 0, mode: 0, sub_mode: 0, vendor_specific_status_code: 0)

Frame tail: D0

Torque control command: 1803FC01 (Frame ID): 00 00 D6 (Data)

Level: 18

Frame type: 03FC (1020)

Source ID: 01

Frame data: 00 00 D6 , Motor channel (00), torque command (00, 00 means torque off)

Frame tail: D6

Read hardware version command:

Request: 18FAE481 (Frame ID): 00 00 02 C0 (Data)

Response: 18FA0164 (Frame ID): 00 02 4E 28 07 D1 C0 (Data)

Request Frame Level: 18

Request Frame Type: FA(250)

Request Frame Source ID: 01

Request Frame Target ID: 64

Request Frame Data: 00 01 02 C0 (Parameter Address: 0001, Parameter Length: 02)

Request Frame Tail: C0

Response Frame Level: 18

Response Frame Type: FA(250)

Response Frame Source ID: 64

Response Frame Target ID: 01

Response Frame Data: 00 02 4E 28 07 D1 (Read Status: 00, Parameter Length: 02, Parameter Data 0: 4E28, Parameter Data 1: 07D1)

Response Frame Tail: C0

3. Servo Memory Map Definition

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The register address uses a paged structure, where each page contains 64 registers. The register address is composed of page number and index. For example, page 1, index 2 corresponds to address 1×64+2=66. All registers in the table can be accessed via MODBUS-RTU and UAVCAN protocols.

3.1 Version Information

Storage: SRAM, Access: Read-only, Write condition: None

Page	Index	Function	Range	Default	Description
0	0	Product Model High Byte		20008
0	1	Product Model Low Byte		2001
0	2	Firmware Version High Byte		2050
0	3	Firmware Version Low Byte		513xx	xx = 00~99
0	4	Byte Order		1	Big-endian format
0	5	SN1		0
0	6	SN2		0
0	7	SN3		0
0	8	SN4		0

3.2 Control Parameters

Storage: SRAM, Access: Read/Write, Write condition: None

Page	Index	Function	Range	Default	Description
1	0	Reserved Address		0
1	1	Reserved Address		0
1	2	Target Position High Byte	0~65535	0	1=0.02197°, -8192~8192 (output shaft -180°~180°)
1	3	Target Position Low Byte	0~65535	0	1=0.02197°, -8192~8192 (output shaft -180°~180°)
1	4	Motion Acceleration	0~2000	Default acceleration	Output shaft acceleration, 1=2.1972°/s², 0 = maximum default
1	5	Motion Speed	-600~600	Default speed	Output shaft speed, 1=0.1831 rpm, 0 = stop
1	6	Motion Current	-625~625	Default current	Operating supply current, 1=6.5 mA
1	7	Torque Limit	0~4800	Default torque limit	Default value is 4800
1	8	Status Reset	0~65535	0	See “Status Reset” bit definition
1	9	Torque Switch	0~1	0	0: torque off; 1: torque on; in servo mode 0 UAVCAN command auto enables torque
1	10	Write Lock Flag	0~11	0	EEPROM parameter unlock flag, unlock value equals page number
1	11	Write Lock Password	-32768~32767	0
1	12	CAN Function Enable Bits	0~7	Default CAN function bits	See “CAN Function Enable Bits”

Status Reset: 0 invalid, 1 reset corresponding fault

Bit / weight description:

BIT10 (1024): reset revolution count
BIT15 (32768): zero calibration

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Note:To reset a fault, set corresponding bit to 1, convert to value, and write it to status reset (1-8).

For example:overheat and overcurrent reset → binary “0000 0000 0000 1100” → hex 000C.

CAN function enable bits: 0 invalid, 1 valid

BIT0: node status auto report enable
BIT1: ----
BIT2: feedback auto report enable

3.3 Status Parameters

Storage: SRAM, Access: Read-only, Write condition: None

Page	Index	Function	Range	Default	Description
2	0	Reserved Address		--
2	1	Reserved Address		--
2	2	Current Position High Byte	0~65535	--	Same unit as target position
2	3	Current Position Low Byte	0~65535	--	Same unit as target position
2	4	Single Turn Position	-32768~32767	--	1=360/16384=0.02197°
2	5	Reserved Address
2	6	Current Speed	-32768~32767	--	1=0.1831 rpm
2	7	Reserved Address		0
2	8	Bus Current	-2048~2047	--	Same unit as motion current
2	9	Voltage	0~400	--	1=0.1 V
2	10	MOS Temperature	0~100	--	1=1°C
2	11	Load	0~5000	--	PWM duty cycle, 1=0.02%
2	12	Servo Status	0~65535	--	See servo status bit definition
2	13	Reserved Address		--
2	14	Motor Temperature	0~100	--	1=1°C
2	15~21	Reserved Address		--
2	22	Input Pulse Width (us)		--	microseconds
2	23	Input Pulse Period (us)		--	microseconds
2	24	Encoder Status Code		--	BIT0~1: normal/strong/weak field; BIT2: button pressed; BIT3: overspeed
2	25	Encoder Error Count		--	Encoder communication error count

Servo Status: 0 indicates normal, 1 indicates abnormal

Bit number / weight: description

BIT0 (1): overvoltage, automatically recovers when voltage is normal
BIT1 (2): undervoltage, automatically recovers when voltage is normal
BIT2 (4): driver MOS over-temperature, automatically recovers when temperature is normal
BIT3 (8): overcurrent, recovers when detected output torque is below safety torque
BIT5 (64): magnetic encoder error, automatically recovers when encoder is normal
BIT7 (128): torque state, 0 = torque OFF, 1 = torque ON
BIT8 (256): motion state, 0 = stopped, 1 = moving
BIT9 (512): target out of range, automatically recovers when valid target is received
BIT12 (4096): target reached status, 0 = reached target
BIT13 (8192): motor MOS over-temperature, automatically recovers when temperature is normal
BIT14 (32768): damping state, 1 = entering damping mode

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Note: If multiple statuses occur simultaneously, the servo status value is the sum of all active bit values.

For example: torque ON + overvoltage ⇒ 128 + 1 = 129

3.4 Communication Parameters

Storage: EPROM, Permission: Read/Write, Write condition: torque switch = 0 && write lock flag = 3

Page	Index	Function	Range	Default	Description
3	0	UART Master ID	1~247	1	Unique device ID on the bus; duplicate IDs are not allowed; 0 is broadcast ID
3	1	Reserved address	–	0	–
3	2	UART baud rate	2~10	4	2-10 correspond to: 256000(2), 128000(3), 115200(4), 57600(5), 38400(6), 19200(7), 14400(8), 9600(9), 4800(10)
3	3	Reserved address	–	0	–
3	4	Reserved address	–	0	–
3	5	UART response delay	0~1000	500	Unit: ms
3	6	Reserved address	–	0	–
3	7	CAN communication timeout	0~1000	100	Unit: ms
3	8	CAN baud rate	0~9	8	0-9 correspond to: 10K(0), 20K(1), 50K(2), 100K(3), 125K(4), 250K(5), 500K(6), 800K(7), 1M(8), 83.3K(9)
3	9	CAN driver node ID	1~125	100	Unique NODE-ID of servo
3	10	CAN controller node ID	1~125	1	Controller NODE-ID; must match controller ID or servo will not accept commands
3	11	Reserved address	0	0	–
3	12	Active reporting frequency	0~32767	100	Unit: ms; interval for feedback auto-report; 0 disables reporting
3	13~17	Reserved address	0	–	–
3	18	CAN heartbeat frequency	0~32767	1000	Unit: ms; status auto-report interval; 0 disables reporting
3	19	Reserved address	0	0	–
3	20	CAN channel ID	0~17	0	UAVCAN position command channel ID

3.5 Configuration Parameters

Storage: EPROM, Permission: Read/Write, Write condition: torque switch = 0 && write lock flag = 4

Page	Index	Function	Range	Default	Description
4	0	Operating mode	0~5	0	0 servo mode, 1 constant speed mode, 2 constant current mode, 3 RCPWM servo mode (reboot required), 4 reserved, 5 motor mode, 6 RCPWM constant speed mode (reboot required)
4	1	Default running speed	0~32767	–	Same unit as running speed
4	2	Default acceleration	0~32767	–	Same unit as running acceleration; 0 = invalid
4	3	Default max current	0~4095	–	Same unit as running current
4	4	Default max torque	0~4800	4800	Same unit as output torque
4	5	Reserved	–	0	–
4	6	Reserved	–	0	–
4	7	Positive direction dead zone	0~128	2	Same unit as target position
4	8	Negative direction dead zone	0~128	2	Same unit as target position
4	9	Minimum angle limit	-8192~0	0	Same unit as target position; min=max means no limit; invalid in RCPWM mode
4	10	Maximum angle limit	0~8191	0	Same unit as target position; min=max means no limit; invalid in RCPWM mode
4	11	Output shaft position offset	-32768~32767	0	Same unit as target position
4	12	Reserved	–	–	–
4	13	CAN function default switch	0~7	5	See CAN function bit definition
4	14	Configuration phase	0~32768	0	Reserved

3.6 RCPWM Parameters

Storage: EPROM, Permission: Read/Write, Write condition: torque switch = 0 && write lock flag = 4

Page	Index	Function	Range	Default	Description
5	0	Min input pulse width	500~2500	500	Unit: μs
5	1	Max input pulse width	500~2500	2500	Unit: μs
5	2	Positive direction pulse width	0~1000	1000	Unit: μs
5	3	Negative direction pulse width	0~1000	1000	Unit: μs
5	4	Signal min angle	-8192~0	-8192	Same unit as target position; PWM mapping; UAVCAN 0~1000 mapping
5	5	Signal max angle	0~8191	8191	Same unit as target position
5	6	Signal resolution	1~16	2	Unit: μs
5	7	Signal trim	-128~128	0	Unit: μs
5	8	Fail-safe protection	0~2	0	0: no torque, 1: go to fail-safe position, 2: hold position
5	9	Fail-safe position	-32768~32767	0	Same unit as target position
5	10	Signal dead zone	0~128	50	RCPWM dead zone in speed mode
5	11	Reserved	–	0	–
5	12	Reserved	–	0	–
5	13	Signal modulation factor	0~512	15	Higher value = faster response when enabled
5	14	Signal phase	0~65535	0	See signal phase bit definition

Signal phase: 0 = OFF, 1 = ON

Bit number / bit weight: description

BIT0 (1): ----
BIT1 (2): ----
BIT2 (4): In RCPWM constant-speed mode, signal and direction phase, 0 = forward direction, 1 = reverse direction
BIT3 (8): In RCPWM servo mode, signal and target position phase, 0 = forward direction, 1 = reverse direction
BIT4 (16): RCPWM signal modulation function bit; effective when firmware version ≥ 2050.51303; 0 = disabled, 1 = enabled (after enabling, weighting is adjusted via the signal modulation coefficient parameter); for fast response applications this bit must be disabled

3.7 Protection Parameters

Storage: EPROM, Permission: Read/Write, Write condition: torque switch = 0 && write lock flag = 7

Page	Index	Function	Range	Default	Description
7	0	Torque shutdown condition	0~65535	7	See “LED alarm / torque shutdown condition” bit definition
7	1	LED alarm condition	0~65535	12295	See “LED alarm / torque shutdown condition” bit definition
7	2	MOS max temperature limit	0~100	70	1 = 1°C
7	3	MOS protection temperature difference	0~10	2	1 = 1°C; overheat recovery temperature = MOS max temperature limit − MOS protection difference
7	4	MOS overheat protection time	0~32767	50	unit: ms
7	5	Minimum input voltage	0~400	80	1 = 0.1V
7	6	Maximum input voltage	0~400	280	1 = 0.1V
7	7	Protection voltage difference	0~20	5	undervoltage recovery voltage = minimum voltage + protection difference; overvoltage recovery voltage = maximum voltage − protection difference
7	8	Undervoltage protection time	0~32767	100	unit: ms
7	9	Overvoltage protection time	0~32767	1000	unit: ms
7	10~12	Reserved	0	0
7	13	Protection current	0~4095	1000	same unit as operating current
7	14	Overcurrent protection time	0~32767	1000	unit: ms
7	15	Safety torque	0~4095	0	maximum torque output after entering overcurrent protection; exits protection when torque drops below this value
7	16~18	Reserved
7	19	Motor max temperature limit	0~100	0	1 = 1°C; 0 disables temperature sensor input
7	20	Motor temperature difference	0~10	2	1 = 1°C; overheat recovery temperature = motor max temperature limit − motor protection difference
7	21	Motor overheat protection time	0~32768	50	unit: ms

LED alarm condition / torque shutdown condition: 0 = OFF, 1 = ON

Bit number / bit weight: description

BIT0 (1): overvoltage alarm / overvoltage protection
BIT1 (2): undervoltage alarm / undervoltage protection
BIT2 (4): MOS overheat alarm / MOS overheat protection, motor overheat alarm / motor overheat protection
BIT3 (8): overcurrent alarm / overcurrent protection
BIT6 (64): terminal magnetic encoder error alarm / protection

3.8 PID Parameters

Storage: EPROM, Permission: Read/Write, Write condition: torque switch = 0 && write lock flag = 8

Page	Index	Function	Range	Default	Description
8	0	Position loop P	0~1000	48
8	1	Position loop D	0~1000	32
8	2	Position loop I	0~1000	0
8	3	Position loop integral limit	0~5000	0	0 = no limit
8	4	Reserved		0
8	5	Speed loop P	0~1000	20
8	6	Speed loop I	0~1000	20
8	7	Reserved		0
8	8	Current loop P	0~1000	0	Reserved
8	9	Current loop I	0~1000	1

1111

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FEETECH UAVCAN Servo – Memory Table Analysis
1. Communication Protocol
2. UAVCAN Command Examples
3. Servo Memory Map Definition
3.1 Version Information
3.2 Control Parameters
3.3 Status Parameters
3.4 Communication Parameters
3.5 Configuration Parameters
3.6 RCPWM Parameters
3.7 Protection Parameters
3.8 PID Parameters