The Modbus protocol is a common language applied to electronic controllers. Based on this protocol, controllers can communicate with each other and with other devices. This protocol has become a general industry standard. This communication protocol enables control devices produced by different manufacturers to be connected into an industrial network for centralized monitoring.

2 硬件配置 Hardware Configuration

3 通信数据帧结构 Data Frame Structure

3.1 读参数命令码0x03 Command code for reading parameter 0x03

请求帧格式 Request frame format

值 Value	描述 Description
ADDR	伺服轴地址：1~247 注：这里1~247为十进制数，需要转换为十六进制数 Servo axis address: 1 to 247. Note: 1 to 247 are decimal values which need to be converted into hexadecimal equivalents.
CMD	命令码：0x03 Command code: 0x03
DATA[0]	寄存器起始地址（高8位）：起始寄存器参数组号如参数H06.11，06即为组号，即DATA[0]=0x06 注：这里06为十六进制数，不需进制转换 Register start address (eight high bits): parameter group number of the start register. Take H06.11 as an example, "06" is the group number, which means DATA[0] = 0x06. Note: In this example, "06" is a hexadecimal value that needs no conversion.
DATA[1]	寄存器起始地址（低8位）：起始寄存器参数组内偏置如参数H06.11，11为组内偏置。即DATA[1]= 0x0B 注：这里11为十进制数，需要转换为十六进制0x0B Register start address (eight low bits): offset within the parameter group of the start register. Take H06.11 as an example, "11" is the offset within the parameter group. That is, DATA [1] = 0x0B. Note: In this example, ''11" is a decimal value that needs to be converted into the hexadecimal equivalent 0x0B.
DATA[2]	读取参数数量的高8位N(H)，十六进制 Read the eight high bits N (H) of the number of parameters (hexadecimal).
DATA[3]	读取参数数量的低8位N(L)，十六进制 Read the eight low bits N (L) of the number of parameters (hexadecimal).
CRCL	CRC校验有效字节(低8位) CRC valid byte (low 8 bits).
CRCH	CRC校验有效字节(高8位) CRC valid byte (high 8 bits).

响应帧格式 Response frame format

值 Value	描述 Description
ADDR	伺服轴地址，十六进制 Servo axis address, hexadecimal.
CMD	命令码：0x03 Command code: 0x03
DATALENGTH	参数字节数，等于读取参数数量N×2 Number of parameter bytes, equal to reading the number of parameters N x 2.
DATA[0]	第一个寄存器参数的数据，高8位 Parameter data in the first register (eight high bits).
DATA[1]	第一个寄存器参数的数据，低8位 Parameter data in the first register (eight low bits).
DATA[...]	...
DATA[N*2-2]	第N个寄存器参数的数据，高8位 Parameter data in the Nth register (eight high bits).
DATA[N*2-1]	第N个寄存器参数的数据，低8位 Parameter data in the Nth register (eight low bits)
CRCL	CRC校验有效字节(低8位) CRC valid byte (low 8 bits).
CRCH	CRC校验有效字节(高8位) CRC valid byte (high 8 bits).

3.1.1 通讯举例 Communication example

从伺服轴地址为01驱动器中，以H02.02为起始寄存器读取2个字长的数据

To read data with a length of two words by taking H02.02 as the start register in the drive whose servo axis address is 01.

主机发送请求帧 Master request frame

CRCL

CRCH

从机响应帧 Slave response frame

CRCL

CRCH

该响应帧表示：从机返回2字长(4个字节)的数据，数据内容为0x0001，0x0000

The response frame indicates the slave returns data with a length of two words (four bytes), the content of which is 0x0001 and 0x0000.

3.2 写参数命令码0x06/0x10 Command code for writing parameters 0x06/0x10

3.2.1 写16位参数命令码0x06 Command code for writing 16-bit parameters 0x06

0x06请求帧格式 0x06 Request frame format

值 Value	描述 Description
ADDR	伺服轴地址：1~247 注：这里1~247为十进制数，需要转换为十六进制数 Servo axis address: 1 to 247. Note: 1 to 247 are decimal values which need to be converted into hexadecimal equivalents.
CMD	命令码：0x06 Command code: 0x06
DATA[0]	寄存器起始地址（高8位）：起始寄存器参数组号如写参数H06.11，06即为组号，即DATA[0]=0x06 注：这里06为十六进制数，不需进制转换 Register start address (eight high bits): parameter group number of the start register. Take H06.11 as an example, "06" is the group number, which means DATA[0] = 0x06. Note: In this example, "06" is a hexadecimal value that needs no conversion.
DATA[1]	寄存器起始地址（低8位）：起始寄存器参数组内偏置如写参数H06.11，11为组内偏置。即DATA[1]= 0x0B 注：这里11为十进制数，需要转换为十六进制0x0B Register start address (eight low bits): offset within the parameter group of the start register. Take H06.11 as an example, "11" is the offset within the parameter group, which means DATA[1] = 0x0B. Note: In this example, ''11" is a decimal value that needs to be converted into the hexadecimal equivalent 0x0B.
DATA[2]	写入寄存器数据高8位，十六进制。 Write the 8 high bits of register data (hexadecimal).
DATA[3]	写入寄存器数据低8位，十六进制。 Write the 8 low bits of register data (hexadecimal).
CRCL	CRC校验有效字节(低8位) CRC valid byte (low 8 bits).
CRCH	CRC校验有效字节(高8位) CRC valid byte (high 8 bits).

0x06响应帧格式 0x06 Response frame format

值 Value	描述 Description
ADDR	伺服轴地址，十六进制 Servo axis address, hexadecimal.
CMD	命令码：0x06 Command code: 0x06
DATA[0]	寄存器起始地址（高8位）：起始寄存器参数组号如写参数H06.11，06即为组号，即DATA[0]=0x06 注：这里06为十六进制数，不需进制转换 Register start address (eight high bits): parameter group number of the start register. Take H06.11 as an example, "06" is the group number, which means DATA[0] = 0x06. Note: In this example, "06" is a hexadecimal value that needs no conversion.
DATA[1]	寄存器起始地址（低8位）：起始寄存器参数组内偏置如写参数H06.11，11为组内偏置。即DATA[1]= 0x0B 注：这里11为十进制数，需要转换为十六进制0x0B Register start address (eight low bits): offset within the parameter group of the start register. Take H06.11 as an example, "11" is the offset within the parameter group, which means DATA[1] = 0x0B. Note: In this example, ''11" is a decimal value that needs to be converted into the hexadecimal equivalent 0x0B.
DATA[2]	写入寄存器数据高8位，十六进制。 Write the 8 high bits of register data (hexadecimal).
DATA[3]	写入寄存器数据低8位，十六进制。 Write the 8 low bits of register data (hexadecimal).
CRCL	CRC校验有效字节(低8位) CRC valid byte (low 8 bits).
CRCH	CRC校验有效字节(高8位) CRC valid byte (high 8 bits).

3.2.1.1 0x06通讯举例 0x06 Communication example

将数据0x0001写入伺服轴地址为01的驱动器参数H02.02中

To write data 0x0001 to H02.02 in the drive whose servo axis address is 01: Master request frame

主机发送请求帧 Master request frame

CRCL

CRCH

从机响应帧 Slave response frame

CRCL

CRCH

该响应帧表示：伺服轴地址为01的驱动器参数H02.02写入数据0x0001

This response frame indicates 0x0001 has been written to H02.02 in the drive whose servo axis address is 01.

3.2.2 写32位参数命令码0x10 Command code for writing 32-bit parameters 0x10

0x10请求帧格式 0x10 Request frame format

值 Value	描述 Description
ADDR	伺服轴地址：1~247 注：这里1~247为十进制数，需要转换为十六进制数 Servo axis address: 1 to 247. Note: 1 to 247 are decimal values which need to be converted into hexadecimal equivalents.
CMD	命令码：0x06 Command code: 0x06
DATA[0]	寄存器起始地址（高8位）：起始寄存器参数组号如写参数H11.12，11即为组号，即DATA[0]=0x11 注：这里06为十六进制数，不需进制转换 Register start address (eight high bits): parameter group number of the start register. Take H11.12 as an example, "11" is the group number, which means DATA[0] = 0x11. Note: In this example, "06" is a hexadecimal value that needs no conversion.
DATA[1]	寄存器起始地址（低8位）：起始寄存器参数组内偏置如写参数H11.12， 12即为组内偏置，即DATA[1]=0x0C 注：这里11为十进制数，需要转换为十六进制0x0B Register start address (eight low bits): offset within the parameter group of the start register. Take H11.12 as an example, "12" is the offset within the parameter group, which means DATA[1] = 0x0C. Note: In this example, ''11" is a decimal value that needs to be converted into the hexadecimal equivalent 0x0B.
DATA[2]	写入参数数量高8位M(H)：十六进制例如只写H05.07，DATA[2]为00，DATA[3]为02，M=H0002 32位参数每个参数按2个word计算 Write the eight high bits M (H) of the number of parameters (hexadecimal. Take H05.07 as an example, DATA[2] is 00, DATA[3] is 02, and M is H0002. For 32-bit parameters, each parameter is calculated as two words.
DATA[3]	写入参数数量低8位M(L)：十六进制 Write the eight low bits M (L) of the number of parameters (hexadecimal).
DATA[4]	写入寄存器的数据对应字节数M×2 例如单写H05.07，DATA[4]为H04 Write the number of bytes (M x 2) corresponding to the register data. Take H05.07 as an example, DATA[4] is H04.
DATA[5]	写入起始寄存器数据高8位，十六进制 Write the eight high bits of the start register data (hexadecimal).
DATA[6]	写入起始寄存器数据低8位，十六进制 Write the eight low bits of the start register data (hexadecimal).
DATA[7]	写入起始寄存器地址+1的数据高8位，十六进制 Write the eight high bits of the start register address +1 (hexadecimal).
DATA[8]	写入起始寄存器地址+1的数据低8位，十六进制 Write the eight low bits of the start register address +1 (hexadecimal).
CRCL	CRC校验有效字节(低8位) CRC valid byte (low 8 bits).
CRCH	CRC校验有效字节(高8位) CRC valid byte (high 8 bits).

0x10响应帧格式 0x10 Response frame format

值 Value	描述 Description
ADDR	伺服轴地址，十六进制 Servo axis address, hexadecimal.
CMD	命令码：0x10 Command code: 0x10
DATA[0]	寄存器起始地址（高8位）：起始寄存器参数组内偏置如写参数H11.12，则DATA[0]为0x11 Register start address (eight high bits): offset within the parameter group of the start register. Take H11.12 as an example, DATA[0] = 0x11.
DATA[1]	寄存器起始地址（低8位）：起始寄存器参数组内偏置如写参数H11.12，则DATA[1]为0x0C Register start address (eight low bits): offset within the parameter group of the start register. Take H11.12 as an example, DATA[1] = 0x0C.
DATA[2]	写入参数数量高8位M(H)：十六进制 Write the eight high bits M (H) of the number of parameters (hexadecimal).
DATA[3]	写入参数数量低8位M(L)：十六进制 Write the eight low bits M (L) of the number of parameters (hexadecimal).
CRCL	CRC校验有效字节(低8位) CRC valid byte (low 8 bits).
CRCH	CRC校验有效字节(高8位) CRC valid byte (high 8 bits).

3.2.2.1 0x10通讯举例 0x10 Communication example

例如向“第1段移动位移H11.12”写入“0x12345678”的Modbus指令：

For example, the Modbus command for writing 0x12345678 to H11.12 (Displacement 1) is as follows:

若H0C.26=1(低16位在前，高16位在后)：

If H0C.26 = 1 (Low 16 bits before high 16 bits):

CRCL

CRCH

若H0C.26=0(高16位在前，低16位在后)：

If H0C-26 = 0 (High 16 bits before low 16 bits):

CRCL

CRCH

4 通信配置实例 Communication Configuration Instance

通信概述 Communication Overview

本案例以写速度(H06.03)和读速度(H0B.00)为例说明

The writing speed (H06-03)and reading speed (H0B-00) are used for illustration.

参数

Parameters

数据类型

Data Type

读/写

R/W

最大值

Max

最小值

Min

单位

Unit

H06.03

有符号16位

Int16

读/写

R/W

6000

-6000

rpm

H0B.00

有符号16位

Int16

读

9999

-9999

rpm

4.1 西门子 S7-200Smart Siemens S7-200Smart

4.1.1 通讯布线 Communication Wiring

西门子S7200 PLC

Siemens S7200 PLC

驱动器侧CN3/CN4端子排序

CN3/CN4 Terminal Layout on Drive Side

PLC 端口0-RS485

PLC PORT0-RS485

针脚号

Pin No.

信号名称

Signal Name

针脚号

Pin No.

RS485+

RS485-

PE(屏蔽网层)

PE (shield layer)

壳体

Enclosure

PE(屏蔽网层)

PE (shield layer)

壳体

Enclosure

4.1.2 伺服参数设置 Servo Parameter Settings

参数 Parameter	设置值 Value	说明 Description	备注 Remarks
H0C.00	1	驱动器轴地址 Drive axis address	-
H0C.02	5	串口波特率设置 Serial baud rate	5：57600bps
H0C.03	3	Modbus数据格式 Modbus data format	3：无校验，1个停止位 3: No parity, 1 stop bit
H0C.26	0	Modbus通讯数据高低位顺序 Modbus communication data sequence	0：高十六位在前，低十六位在后 1：低十六位在前，高十六位在后 0: High 16 bits before low 16 bits 1: Low 16 bits before high 16 bits

4.1.3 PLC程序示例 PLC Program Examples

主站初始化 Master Initialize

读取速度 Reading Speed

1秒钟读取一次速度(H0B.00) Read speed once per second(H0B.00)

地址计算伪代码 Address calculation pseudocode

如果 (十六进制转十进制(组号+00)+组内偏置>9999)
{
  十六进制转十进制(组号+00)+组内偏置+400001;
}
否则
{
  十六进制转十进制(组号+00)+组内偏置+40001;
}

if (Hexadecimal To Decimal(group number+00)+group offset>9999)
{
   Hexadecimal To Decimal(group number+00)+group offset+400001;
}
else
{
  Hexadecimal To Decimal(group number+00)+group offset+40001;
}