modbus在java中的使用，首先maven的pom中引入modbus4j包

com.infiniteautomation

modbus4j

3.0.3

2. 我们创建类：ModBus4JTCPClient，创建ModbusMaster连接对象，以及读取寄存器方法

package io.powerx.test;

import org.apache.commons.lang3.StringUtils;

import com.serotonin.modbus4j.ModbusFactory;

import com.serotonin.modbus4j.ModbusMaster;

import com.serotonin.modbus4j.code.DataType;

import com.serotonin.modbus4j.exception.ErrorResponseException;

import com.serotonin.modbus4j.exception.ModbusInitException;

import com.serotonin.modbus4j.exception.ModbusTransportException;

import com.serotonin.modbus4j.ip.IpParameters;

import com.serotonin.modbus4j.locator.BaseLocator;

import com.serotonin.modbus4j.msg.ModbusResponse;

import com.serotonin.modbus4j.msg.WriteRegisterRequest;

import com.serotonin.modbus4j.msg.WriteRegistersRequest;

public class ModBus4JTCPClient {

private ModbusFactory modbusFactory;

public ModbusFactory getModbusFactory() {

if (modbusFactory == null) {

modbusFactory = new ModbusFactory();

}

return modbusFactory;

}

/**

*

* @param ip

* @param port

* @return

* @throws ModbusInitException

*/

public ModbusMaster getMaster(String ip, int port) throws ModbusInitException {

ModbusMaster m = null;

IpParameters tcpParameters = new IpParameters();

tcpParameters.setHost(ip);

tcpParameters.setPort(port);

m = getModbusFactory().createTcpMaster(tcpParameters, false);

m.setTimeout(2000);

m.init();

return m;

}

/**

* Holding Register类型

*

* @param master

* @param modbusId

* @param registerId

* @param registerNumber

* @param analysisFlag

* @return

* @throws ModbusTransportException

* @throws ErrorResponseException

* @throws ModbusInitException

*/

public Number readHoldingRegister(ModbusMaster master, int modbusId, int registerId, int registerNumber,

String analysisFlag) throws ModbusTransportException, ErrorResponseException, ModbusInitException {

Number value = null;

if ("u".equals(analysisFlag)) {

value = holdingRegister_UNSIGNED(master, modbusId, registerId, registerNumber);

} else if ("s".equals(analysisFlag)) {

value = holdingRegister_SIGNED(master, modbusId, registerId, registerNumber);

}

return value;

}

public Number holdingRegister_UNSIGNED(ModbusMaster master, int modbusId, int registerId, int registerNumber)

throws ModbusTransportException, ErrorResponseException {

BaseLocator loc = BaseLocator.holdingRegister(modbusId, registerId - 1,

(registerNumber == 1) ? DataType.TWO_BYTE_INT_UNSIGNED : DataType.FOUR_BYTE_INT_UNSIGNED);

return master.getValue(loc);

}

public Number holdingRegister_SIGNED(ModbusMaster master, int modbusId, int registerId, int registerNumber)

throws ModbusTransportException, ErrorResponseException {

return master.getValue(BaseLocator.holdingRegister(modbusId, registerId - 1,

(registerNumber == 1) ? DataType.TWO_BYTE_INT_SIGNED : DataType.FOUR_BYTE_INT_SIGNED));

}

// Input Registers

public void readInputRegisters(ModbusMaster master, int registerId, int registerNumber, int modbusId,

String analysisFlag) throws ModbusTransportException, ErrorResponseException, ModbusInitException {

Number value = null;

//z代表是正数，s代表可能是负数

if ("z".equals(analysisFlag)) {

value = inputRegister_UNSIGNED(master, modbusId, registerId, registerNumber);

} else if ("f".equals(analysisFlag)) {

value = inputRegister_SIGNED(master, modbusId, registerId, registerNumber);

}

}

public Number inputRegister_UNSIGNED(ModbusMaster master, int modbusId, int registerId, int registerNumber)

throws ModbusTransportException, ErrorResponseException {

return master.getValue(BaseLocator.inputRegister(modbusId, registerId - 1,

(registerNumber == 1) ? DataType.TWO_BYTE_INT_UNSIGNED : DataType.FOUR_BYTE_INT_UNSIGNED));

}

public Number inputRegister_SIGNED(ModbusMaster master, int modbusId, int registerId, int registerNumber)

throws ModbusTransportException, ErrorResponseException {

return master.getValue(BaseLocator.inputRegister(modbusId, registerId - 1,

(registerNumber == 1) ? DataType.TWO_BYTE_INT_SIGNED : DataType.FOUR_BYTE_INT_SIGNED));

}

/**

* 写入寄存器

*

* @param master

* @param registerId

* @param modbusId

* @param sdata

* @return

* @throws ModbusTransportException

* @throws ModbusInitException

*/

public boolean writeRegister(ModbusMaster master, int registerId, int modbusId, short sdata)

throws ModbusTransportException, ModbusInitException {

// 创建请求对象

WriteRegisterRequest request = new WriteRegisterRequest(modbusId, registerId - 1, sdata);

// 发送请求并获取响应对象

ModbusResponse response = master.send(request);

if (response.isException()) {

return false;

} else {

return true;

}

}

public boolean writeRegisters(ModbusMaster master, int registerId, int modbusId, short[] sdata)

throws ModbusTransportException, ModbusInitException {

// 创建请求对象

WriteRegistersRequest request = new WriteRegistersRequest(modbusId, registerId - 1, sdata);

// 发送请求并获取响应对象

ModbusResponse response = master.send(request);

if (response.isException()) {

return false;

} else {

return true;

}

}

public void writeHoldingRegister(ModbusMaster master, int registerId, int modbusId, Number writeValue, int dataType)

throws ModbusTransportException, ErrorResponseException, ModbusInitException {

BaseLocator locator = BaseLocator.holdingRegister(modbusId, registerId - 1,

(dataType == 1) ? DataType.TWO_BYTE_INT_UNSIGNED : DataType.FOUR_BYTE_INT_UNSIGNED);

master.setValue(locator, writeValue);

}

}

3. 我们试一下在main方法中调用

int registerId=100;

int modbusId=1;

ModBus4JTCPClient modbusTcp = new ModBus4JTCPClient();

ModbusMaster master = modbusTcp.getMaster("localhost", 502);//192.168.1.108

modbusTcp.readInputRegisters(master, registerId, 1, modbusId, "u");