UART Communication Function Usage

UART Communication Protocol

• Baud Rate: 115200
• Data Bits: 8 bits
• Stop Bits: 1 bit
• Parity: None
• Response Mode: Query‑and‑response

The UART communication protocol uses a fixed 10‑byte frame format:

Device Address	Command Code	Object Address		Error/Clear	Data Field				Checksum
Byte1	Byte2	Byte3	Byte4	Byte5	Byte6	Byte7	Byte8	Byte9	Byte10
ID	CMD	AddrH	AddrL	ErrR	Data(MSB)	Data(N-1)	Data(N-2)	Data(LSB)	Check

• ID: Slave device address, default value: 0x01. The device will return no response if the ID does not match.
  
• CMD: Command code, including read command 0xA0 and write commands 0x51, 0x52, 0x54.
  Detailed definition of command codes is shown below:
  

  • Read Command: Host reads data from the specified object address on the drive

    Host‑sent CMD	Drive Response CMD	Description
    0xA0	By0xA1	Object data is 8‑bit: [Data(LSB)]
    0xA0	0xA2	Object data is 16‑bit: [Data(N‑2) - Data(LSB)]
    0xA0	0xA4	Object data is 32‑bit: [Data(MSB) - Data(LSB)]
    0xA0	0x5F	Object address does not exist; data field is invalid
    0xA0	0x80	Checksum error; data field is invalid

  • Write Command: Host writes data to the specified object address on the drive

    Host‑sent CMD	Drive Response CMD	Description
    0x51	0x61	8‑bit object data: [Data4], write succeeded
    	0x50	Data type mismatch, write failed
    	0x58	Object address is read‑only, write failed
    	0x5F	Object address does not exist, write failed
    0x52	0x62	16‑bit object data: [Data3 - Data4], write succeeded
    	0x50	Data type mismatch, write failed
    	0x58	Object address is read‑only, write failed
    	0x5F	Object address does not exist, write failed
    0x54	0x64	32‑bit object data: [Data1 - Data4], write succeeded
    	0x50	Data type mismatch, write failed
    	0x58	Object address is read‑only, write failed
    	0x5F	Object address does not exist, write failed

• AddrH, AddrL: High‑byte and low‑byte of the object address
• ErrR: Error Report & Clear
  • When ErrR = 0xCE in any valid host read/write frame, the drive's error flag will be cleared.
  • The value returned in ErrR by the drive contains fault information. Each of the 8 bits represents one fault condition: 0 = no fault, 1 = fault detected. Fault definitions are listed below:

    ErrR returned by device	Error description
    bit0: [LSB]	Reserved
    bit1:	Following error exceeds allowed value
    bit2:	Encoder error
    bit3:	Motor overload
    bit4:	Drive over‑temperature
    bit5:	DC‑bus voltage too high
    bit6:	DC‑bus voltage too low
    bit7: [MSB]	Drive output short circuit

• Data(MSB)-Data(LSB): Data field, most significant byte first, least significant byte last.
• Check: Checksum, Check = sum of [Byte1-Byte9] taken as the lower 8 bits.

UART Communication Examples

Example 1: Read the actual DC‑bus voltage of the drive
Referring to "Table F1‑3 Measured Data" in Object Dictionary List, the object address for "Actual DC‑bus Voltage" is 0x5001, stored as a 16‑bit signed integer. Assume the actual DC‑bus voltage is 36 V.

	Device Address	Command Code	Object Address		Error/Clear	Data Field				Checksum
Host Send	0x01	0xA0	0x50	0x01	0x00	0x00	0x00	0x00	0x00	0xF2
Drive Response	0x01	0xA2	0x50	0x01	0x00	0x00	0x00	0x00	0x24	0x18

Example 2: Read the actual motor encoder position
Referring to "Table F1‑3 Measurement Data" in the Common Object List, the object address for "Actual Position Value" is 0x7071, stored as a 32‑bit signed integer.

	Device Address	Command Code	Object Address		Error/Clear	Data Field				Checksum
Host Send	0x01	0xA0	0x70	0x71	0x00	0x00	0x00	0x00	0x00	0x82
Assume the current encoder actual position = -8237, hexadecimal: 0xFFFFDFD3
Drive Response	0x01	0xA4	0x70	0x71	0x00	0xFF	0xFF	0xDF	0xD3	0x36
If the drive has an error, e.g., "Following error exceeds allowed value"
Drive Fault Response	0x01	0xA4	0x70	0x71	0x02	0xFF	0xFF	0xDF	0xD3	0x38

Example 3: Write target speed (rpm)
Referring to "Table F1‑2 Basic Modes & Control" in Object Dictionary List, the object address for Target Speed (rpm) is 0x70B1, stored as a 16‑bit signed integer. Assume the value to be written = 100, hexadecimal: 0x0064.

	Device Address	Command Code	Object Address		Error/Clear	Data Field				Checksum
Host Send	0x01	0x52	0x70	0xB1	0x00	0x00	0x00	0x00	0x64	0xD8
Drive Response	0x01	0x62	0x70	0xB1	0x00	0x00	0x00	0x00	0x64	0xE8

Example 4: Write Target Speed (High‑resolution speed command)
Referring to "Table F1‑2 Basic Modes & Control" in Object Dictionary List, the object address for High‑Precision Target Speed is 0x70B2, stored as a 32‑bit signed integer.
To set a speed command of 3.21 rpm, apply the conversion formula:
U[y,x]:[DEC]=([rpm] * 512 * [Feedback_Resolution])/1875. Where Feedback_Resolution = 4096.
DEC = (3.21 × 512 × 4096) / 1875 = 3590, hexadecimal: 0x0E06.

	Device Address	Command Code	Object Address		Error/Clear	Data Field				Checksum
Host Send	0x01	0x54	0x70	0xB2	0x00	0x00	0x00	0x0E	0x06	0x8B
Drive Response	0x01	0x64	0x70	0xB2	0x00	0x00	0x00	0x0E	0x06	0x9B