Template: Modbus RTU Analog Output 8CH Protocol
Development Protocol
Function Code Introduction
| Function Code | Note |
|---|---|
| 03 | Read Holding Registers |
| 06 | Write Single Holding Register |
| 10 | Write Multiple Holding Register |
Register Address Introduction
| Address (HEX) | Address Storage Content | Register Value | Permissions | Modbus Function Code |
|---|---|---|---|---|
| 4x0000 …… 4x0007 |
Channel 1 ~ 8 Output Data | Unsigned hexadecimal | Read/Write | 0x03, 0x06, 0x10 |
| 4x2000 | Serial port parameters | High 8-bit is the parity mode: 0x00~0x02 Low 8-bit is the baud rate mode: 0x00~0x07 |
Read/Write | 0x03, 0x06 |
| 4x4000 | Device address | Direct store Modbus addresses Device address: 0x0001-0x00FF |
Read/Write | 0x03, 0x06 |
| 4x8000 | Software version | Convert to decimal and then shift the decimal point two places to the left to represent the software version 0x0064 = 100 = V1.00 |
Read | 0x03 |
Set Single-channel Output Command
Send code: 01 06 00 00 03 E8 89 74
| Fields | Description | Note |
|---|---|---|
| 01 | Device Address | 0x00 indicates the broadcast address, 0x01-0xFF indicates the device address |
| 06 | 06 Command | Write a single register command |
| 00 00 | Register Address | 0x0000 - 0x0007 corresponds to 1~8 channel output data |
| 03 E8 | Value Setting | Set the value to hexadecimal, unit in uA, high bits in the front, low bits at the end 0x03E8 = 1000uA, or 1mA |
| 89 74 | CRC16 | CRC16 checksum of the first 6 bytes of data |
Receive code: 01 06 00 00 03 E8 89 74
| Fields | Description | Note |
|---|---|---|
| 01 | Device Address | 0x00 indicates the broadcast address, 0x01-0xFF indicates the device address |
| 06 | 06 Command | Write a single register command |
| 00 00 | Register Address | 0x0000 - 0x0007 corresponds to 1~8 input channel data type |
| 03 E8 | Value Setting | Set the value in hexadecimal, unit mV, high bits in the front, low bits in the end. 0x03E8 = 1000mV, or 1V |
| 89 74 | CRC16 | CRC16 checksum of the first 6 bytes of data |
For example:
[No.1 address device]
Set channel 1 output 1mA : 01 06 00 00 03 E8 89 74
Read channel 2 output 5mA : 01 06 00 01 13 88 D5 5C
Set Multiple-channel Output Command
Send command: 01 10 00 00 00 08 10 03 E8 03 E8 03 E8 03 E8 03 E8 03 E8 03 E8 03 E8 3C 05
| Fields | Description | Note |
|---|---|---|
| 01 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates the device address |
| 10 | 10 Command | Write multi-register command |
| 00 00 | Register Initial Address | 0x0000 - 0x0007 corresponds to 1~8 output channels |
| 00 08 | Register Numbers | Set the number of registers, up to 8 channels |
| 10 | Bytes Numbers | Set the output bytes |
| 03 E8 …… 03 E8 |
Command | Channel 1 analog output …… Channel 8 analog output Set the value in hexadecimal, unit in mV, high bits in the front, low bits in the end 0x03E8 = 1000uA, or 1mA |
| 3C 05 | CRC16 | CRC16 checksum of the first 6 bytes of data |
Receive code: 01 10 00 00 00 08 C1 CF
| Fields | Description | Note |
|---|---|---|
| 01 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 10 | 10 Command | Write multi-register command |
| 00 00 | Register Initial Address | 0x0000 - 0x0007 corresponds to 1~8 output channels |
| 00 08 | Register Numbers | Set the register numbers, up to 8 channels |
| C1 CF | CRC16 | CRC16 checksum of the first 6 bytes of data |
For example:
[No.1 address device]
Set channel 1-8 output 1mA: 01 10 00 00 00 08 10 03 E8 03 E8 03 E8 03 E8 03 E8 03 E8 03 E8 03 E8 3C 05
Set channel 3-5 output 2mA: 01 10 00 02 00 03 06 07 D0 07 D0 07 D0 84 0E
Read Channel Output Command
Send code: 01 03 00 00 00 08 44 0C
| Fields | Description | Note |
|---|---|---|
| 01 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 03 | 03 Command | Read holding register |
| 00 00 | Register Initial Address | 0x0000 - 0x0007 corresponds to 1~8 input channels |
| 00 08 | Register Numbers | Read the register numbers, up to 8 channels |
| 44 0C | CRC16 | CRC16 checksum of the first 6 bytes of data |
Receive code: 01 03 10 03 E8 03 E8 03 E8 03 E8 03 E8 03 E8 03 E8 03 E8 C1 91
| Fields | Description | Note |
|---|---|---|
| 01 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 03 | 03 Command | Read holding register |
| 10 | Byte Numbers | Number of bytes for returning status information |
| 03 E8 …… 03 E8 |
Output Value | Channel 1 analog output …… Channel 8 analog output Set the value in hexadecimal, unit mV, high bits in the front, low bits in the end 0x03E8 = 1000uA, or 1mA |
| C1 91 | CRC16 | CRC16 checksum of the first 6 bytes of data |
For example
[No.1 address device]
Read channel 1-8 data type: 01 03 00 00 00 08 44 0C
Read channel 1 data type: 01 03 00 00 00 01 84 0A
Read channel 2 data type: 01 03 00 01 00 01 D5 CA
Read channel 3-5 data type: 01 03 00 02 00 03 A4 0B
Set Baudrate Command
Send code: 00 06 20 00 00 05 43 D8
| Fields | Description | Note |
|---|---|---|
| 00 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 06 | 06 Command | Set the baud rate and device addresses |
| 20 00 | Command Register | 0x2000 for setting baudrate, 0x4000 for setting device addresses |
| 00 | Parity Method | 0x00 is no parity, 0x01 is even parity, 0x02 is odd parity |
| 05 | Baudrate Value | 0x00: 4800 0x01: 9600 0x02: 19200 0x03: 38400 0x04: 57600 0x05: 115200 0x06: 128000 0x07: 256000 |
| 43 D8 | CRC16 | CRC16 checksum of the first 6 bytes of data |
Receive code: 00 06 20 00 00 05 43 D8
| Fields | Description | Note |
|---|---|---|
| 00 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 06 | 06 Command | Set the baud rate and device addresses |
| 20 00 | Command Register | 0x2000 is setting the baud rate, 0x4000 is setting the device address |
| 00 | Parity Method | 0x00 is no parity, 0x01 is even parity, 0x02 is odd parity |
| 05 | Baudrate | 0x00: 4800 0x01: 9600 0x02: 19200 0x03: 38400 0x04: 57600 0x05: 115200 0x06: 128000 0x07: 256000 |
| 43 D8 | CRC16 | CRC16 checksum of the first 6 bytes of data |
For example:
[No.1 address device]
Set baud rate 4800: 00 06 20 00 00 00 83 DB
Set baud rate 9600: 00 06 20 00 00 01 42 1B
Set baud rate 115200: 00 06 20 00 00 05 43 D8
Set Device Address Command
Sending code: 00 06 40 00 00 01 5C 1B
| Fields | Description | Note |
|---|---|---|
| 00 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 06 | 06 Command | Set the baud rate and device addresses |
| 40 00 | Command Register | 0x2000 is setting baudrate, 0x4000 is setting the device address |
| 00 01 | Device Address | Set the device address: 0x0001-0x00FF |
| 5C 1B | CRC16 | CRC16 checksum of the first 6 bytes of data |
Receive code: 00 06 40 00 00 01 5C 1B
| Fields | Description | Note |
|---|---|---|
| 00 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 06 | 06 Command | Set the baud rate and device addresses |
| 40 00 | Command Register | 0x2000 is setting baudrate, 0x4000 is setting the device address |
| 00 01 | Device Address | Set the device address, 0x0001-0x00FF |
| 5C 1B | CRC16 | CRC16 checksum of the first 6 bytes of data |
For example:
[No.1 address device]
Set the device address as 0x01: 00 06 40 00 00 01 5C 1b
Set the device address as 0x02: 00 06 40 00 00 02 1C 1A
Set the device address as 0x03: 00 06 40 00 00 03 DD DA
Read Device Address Command
Send code: 00 03 40 00 00 01 90 1B
| Fields | Description | Note |
|---|---|---|
| 00 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 03 | 03 Command | Read device address command |
| 40 00 | Command Register | 0x4000 for read device address, 0x8000 for read software version |
| 00 01 | Byte Numbers | Fixed 0x0001 |
| 90 1B | CRC16 | CRC16 checksum of the first 6 bytes of data |
Received code: 01 03 02 00 01 79 84
| Fields | Description | Note |
|---|---|---|
| 00 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 03 | 03 Command | Read the software version and the device address |
| 02 | Byte Numbers | Return byte numbers |
| 00 01 | Device Address | Set the device address: 0x0001-0x00FF |
| 79 84 | CRC16 | CRC16 checksum of the first 6 bytes of data |
For example:
[No.1 address device]
Send: 00 03 40 00 00 01 90 1B
Receive: 01 03 02 00 01 79 84 //address 0x01
[No.2 address device]
Send: 00 03 40 00 00 01 90 1B
Receive: 02 03 02 00 02 7D 85 //address 0x02
[No.3 address device]
Send: 00 03 40 00 00 01 90 1B
Receive: 03 03 02 00 03 81 85 //address 0x03
Read Software Version Command
Sending code: 00 03 80 00 00 01 AC 1B
| Fields | Description | Note |
|---|---|---|
| 01 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 03 | 03 Command | Read the software version and the device address |
| 80 00 | Command Register | 0x4000 is reading software version, 0x8000 is reading device address |
| 00 01 | Byte Numbers | Fixed 0x0001 |
| 8F CA | CRC16 | CRC16 checksum of the first 6 bytes of data |
Receive code: 01 03 02 00 64 B9 AF
| Fields | Description | Note |
|---|---|---|
| 01 | Device Address | 0x00 indicates the broadcast address; 0x01-0xFF indicates device address |
| 03 | 03 Command | Read the software version and the device address |
| 02 | Byte Numbers | Received Byte Numbers |
| 00 64 | Software Version | Convert to decimal and then shift the decimal point two places to the left to represent the software version. 0x0064 = 100 = V1.00 |
| B9 AF | CRC16 | CRC16 checksum of the first 6 bytes of data |
For example:
[No.1 address device]
Send: 00 03 80 00 00 01 AC 1B
Receive: 01 03 02 00 64 B9 AF //0x0064 = 100 =V1.00