函数列表

函数	说明
modbus	创建MODBUS对象
read	从MODBUS服务器读取数据
write	对连接的MODBUS服务器执行写操作
writeRead	在单个MODBUS事务中对一组保持寄存器执行写然后读操作
maskWrite	在保持寄存器上执行掩码写入操作
instrhwinfo	有关可用硬件的信息
clear	从MATLAB工作区中删除仪器对象

配置说明

Property	Transport Type	Description
‘DeviceAddress’	TCP/IP only	IP address or host name of MODBUS server, for example, ‘192.168.2.1’. Required during object creation if transport is TCP/IP.`m = modbus('tcpip', '192.168.2.1')`
Port	TCP/IP only	Remote port used by MODBUS server. The default is 502. Optional during object creation if transport is TCP/IP.`m = modbus('tcpip', '192.168.2.1', 308)`
‘Port’	Serial RTU only	Serial port MODBUS server is connected to, for example, ‘COM1’. Required during object creation if transport is Serial RTU.`m = modbus('serialrtu','COM3')`
Timeout	Both TCP/IP and Serial RTU	Maximum time in seconds to wait for a response from the MODBUS server, specified as a positive value of type double. The default is 10. You can change the value either during object creation, or after you create the object.`m.Timeout = 30;`
NumRetries	Both TCP/IP and Serial RTU	Number of retries to perform if there is no reply from the server after a timeout. If using the Serial RTU transport, the message is resent. If using the TCP/IP transport, the connection is closed and reopened.`m.NumRetries = 5;`
‘ByteOrder’	Both TCP/IP and Serial RTU	Byte order of values written to or read from 16-bit registers. Valid choices are ‘big-endian’ and ‘little-endian’. The default is ‘big-endian’, as specified by the MODBUS standard.`m.ByteOrder = 'little-endian';`
‘WordOrder’	Both TCP/IP and Serial RTU	Word order for register reads and writes that span multiple 16-bit registers. Valid choices are ‘big-endian’ and ‘little-endian’. The default is ‘big-endian’, and it is device-dependent.`m.WordOrder = 'little-endian';`
BaudRate	Serial RTU only	Bit transmission rate for serial port communication. Default is 9600 bits per seconds, but the actual required value is device-dependent.`m.Baudrate = 28800;`
DataBits	Serial RTU only	Number of data bits to transmit. Default is 8, which is the MODBUS standard for Serial RTU. Other valid values are 5, 6, and 7.`m.DataBits = 6;`
Parity	Serial RTU only	Type of parity checking. Valid choices are ‘none’ (default), ‘even’, ‘odd’, ‘mark’, and ‘space’. The actual required value is device-dependent. If set to the default of none, parity checking is not performed, and the parity bit is not transmitted.`m.Parity = 'odd';`
StopBits	Serial RTU only	Number of bits used to indicate the end of data transmission. Valid choices are 1 (default) and 2. Actual required value is device-dependent, though 1 is typical for even/odd parity and 2 for no parity.`m.StopBits = 2;`

使用Modbus Slave模拟服务器，数值如下设置：

注意：Modbus Slave中每个寄存器是16位！

数据类型有：'int16', 'uint16', 'int32', 'uint32', 'single', 'double', 'int64', 'uint64'

数据读取

% 创建客户端m = modbus('tcpip','127.0.0.1',502)% 属性查看>> m.ByteOrderans =    'big-endian'>> m.Portans =   502% 设置属性>> m.Timeout = 3m = Modbus TCPIP with properties:    DeviceAddress: '127.0.0.1'             Port: 502           Status: 'Connected'       NumRetries: 1          Timeout: 3 (seconds)        ByteOrder: 'big-endian'        WordOrder: 'big-endian'  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% read(obj,'holdingregs',address,count)% read(obj,target,address,count,serverId)  % 指定Server ID% read(obj,target,address,count,precision) % 指定数据读取格式% read(obj,target,address,count,serverId,precision) % 同时指定Server ID和数据读取格式% 读取23，以保持寄存器的方式读取，read列表为modbus对象、寄存器类型、开始地址（从1开始）、读取的个数、读取的类型>> read(m,'holdingregs',3,1,'int16')ans =    23% 单精度浮点型数据的读取，注意MATLAB默认的读取字序对应的Slave中的字序为Float AB CD，即大端>> read(m,'holdingregs',5,1,'single')ans =   10.1100% 断开并清除Modbus连接clear m

数据发送

% 创建客户端m = modbus('tcpip','127.0.0.1',502)%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% write(m,target,address,values)% write(m,target,address,values,serverId,'precision')write(mbConnector,'holdingregs',10,1235,'int16')write(mbConnector,'holdingregs',1,[1 2 3],'int16')% 断开并清除Modbus连接clear m

在这里插入图片描述