Java实现ModbusTCP通信功能

<dependency>
<groupId>com.intelligt.modbus</groupId>
<artifactId>jlibmodbus</artifactId>
<version>1.2.9.7</version>
</dependency>

package com.tcb.jlibmodbus;

import java.net.InetAddress;

import com.intelligt.modbus.jlibmodbus.Modbus;
import com.intelligt.modbus.jlibmodbus.exception.ModbusIOException;
import com.intelligt.modbus.jlibmodbus.exception.ModbusNumberException;
import com.intelligt.modbus.jlibmodbus.exception.ModbusProtocolException;
import com.intelligt.modbus.jlibmodbus.master.ModbusMaster;
import com.intelligt.modbus.jlibmodbus.master.ModbusMasterFactory;
import com.intelligt.modbus.jlibmodbus.tcp.TcpParameters;


/**
 * Hello world!
 *
 */
public class App {
	public static void main(String[] args) {
		try {
			// 设置主机TCP参数
			TcpParameters tcpParameters = new TcpParameters();
 
			// 设置TCP的ip地址
			InetAddress adress = InetAddress.getByName("127.0.0.1");
 
			// TCP参数设置ip地址
			// tcpParameters.setHost(InetAddress.getLocalHost());
			tcpParameters.setHost(adress);
 
			// TCP设置长连接
			tcpParameters.setKeepAlive(true);
			// TCP设置端口，这里设置是默认端口502
			tcpParameters.setPort(Modbus.TCP_PORT);
 
			// 创建一个主机
			ModbusMaster master = ModbusMasterFactory.createModbusMasterTCP(tcpParameters);
			Modbus.setAutoIncrementTransactionId(true);
 
			int slaveId = 1;//从机地址
			int offset = 0;//寄存器读取开始地址
			int quantity = 10;//读取的寄存器数量
 
 
			try {
				if (!master.isConnected()) {
					master.connect();// 开启连接
				}
 
				// 读取对应从机的数据，readInputRegisters读取的写寄存器，功能码04
				int[] registerValues = master.readInputRegisters(slaveId, offset, quantity);
 
				// 控制台输出
				for (int value : registerValues) {
					System.out.println("Address: " + offset++ + ", Value: " + value);
				}
 
			} catch (ModbusProtocolException e) {
				e.printStackTrace();
			} catch (ModbusNumberException e) {
				e.printStackTrace();
			} catch (ModbusIOException e) {
				e.printStackTrace();
			} finally {
				try {
					master.disconnect();
				} catch (ModbusIOException e) {
					e.printStackTrace();
				}
			}
		} catch (RuntimeException e) {
			throw e;
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.tcb</groupId>
  <artifactId>modbus</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>modbus</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  
  <!-- 若想引用modbus4j需要引入下列repository id:ias-snapshots id:ias-releases 两个 ，使用默认仓库下载，不要使用阿里云仓库-->
    <repositories>
	    <repository>
	        <releases>
	            <enabled>false</enabled>
	        </releases>
	        <snapshots>
	            <enabled>true</enabled>
	        </snapshots>
	        <id>ias-snapshots</id>
	        <name>Infinite Automation Snapshot Repository</name>
	        <url>https://maven.mangoautomation.net/repository/ias-snapshot/</url>
	    </repository>
	    <repository>
	        <releases>
	            <enabled>true</enabled>
	        </releases>
	        <snapshots>
	            <enabled>false</enabled>
	        </snapshots>
	        <id>ias-releases</id>
	        <name>Infinite Automation Release Repository</name>
	        <url>https://maven.mangoautomation.net/repository/ias-release/</url>
	    </repository>
	</repositories>
	
    <dependencies>
		 <dependency>
		    <groupId>junit</groupId>
		    <artifactId>junit</artifactId>
		    <version>4.13-beta-3</version>
		    <scope>test</scope>
		</dependency>
		<dependency>
		    <groupId>com.infiniteautomation</groupId>
		    <artifactId>modbus4j</artifactId>
		    <version>3.0.3</version>
		</dependency>
		
		<dependency>
		    <groupId>org.apache.commons</groupId>
		    <artifactId>commons-lang3</artifactId>
		    <version>3.9</version>
		</dependency>
    </dependencies>

</project>

package com.tcb.modbus;

import com.serotonin.modbus4j.BatchRead;
import com.serotonin.modbus4j.BatchResults;
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;

/**
 * modbus通讯工具类,采用modbus4j实现
 * 
 * @author lxq
 * @dependencies modbus4j-3.0.3.jar
 * @website https://github.com/infiniteautomation/modbus4j
 */
public class Modbus4jUtils {
	/**
	 * 工厂。
	 */
	static ModbusFactory modbusFactory;
	static {
		if (modbusFactory == null) {
			modbusFactory = new ModbusFactory();
		}
	}

	/**
	 * 获取master
	 * 
	 * @return
	 * @throws ModbusInitException
	 */
	public static ModbusMaster getMaster() throws ModbusInitException {
		IpParameters params = new IpParameters();
		params.setHost("localhost");
		params.setPort(502);
		//
		// modbusFactory.createRtuMaster(wapper); //RTU 协议
		// modbusFactory.createUdpMaster(params);//UDP 协议
		// modbusFactory.createAsciiMaster(wrapper);//ASCII 协议
		ModbusMaster master = modbusFactory.createTcpMaster(params, false);// TCP 协议
		master.init();

		return master;
	}

	/**
	 * 读取[01 Coil Status 0x]类型 开关数据
	 * 
	 * @param slaveId
	 *            slaveId
	 * @param offset
	 *            位置
	 * @return 读取值
	 * @throws ModbusTransportException
	 *             异常
	 * @throws ErrorResponseException
	 *             异常
	 * @throws ModbusInitException
	 *             异常
	 */
	public static Boolean readCoilStatus(int slaveId, int offset)
			throws ModbusTransportException, ErrorResponseException, ModbusInitException {
		// 01 Coil Status
		BaseLocator<Boolean> loc = BaseLocator.coilStatus(slaveId, offset);
		Boolean value = getMaster().getValue(loc);
		return value;
	}

	/**
	 * 读取[02 Input Status 1x]类型 开关数据
	 * 
	 * @param slaveId
	 * @param offset
	 * @return
	 * @throws ModbusTransportException
	 * @throws ErrorResponseException
	 * @throws ModbusInitException
	 */
	public static Boolean readInputStatus(int slaveId, int offset)
			throws ModbusTransportException, ErrorResponseException, ModbusInitException {
		// 02 Input Status
		BaseLocator<Boolean> loc = BaseLocator.inputStatus(slaveId, offset);
		Boolean value = getMaster().getValue(loc);
		return value;
	}

	/**
	 * 读取[03 Holding Register类型 2x]模拟量数据
	 * 
	 * @param slaveId
	 *            slave Id
	 * @param offset
	 *            位置
	 * @param dataType
	 *            数据类型,来自com.serotonin.modbus4j.code.DataType
	 * @return
	 * @throws ModbusTransportException
	 *             异常
	 * @throws ErrorResponseException
	 *             异常
	 * @throws ModbusInitException
	 *             异常
	 */
	public static Number readHoldingRegister(int slaveId, int offset, int dataType)
			throws ModbusTransportException, ErrorResponseException, ModbusInitException {
		// 03 Holding Register类型数据读取
		BaseLocator<Number> loc = BaseLocator.holdingRegister(slaveId, offset, dataType);
		Number value = getMaster().getValue(loc);
		return value;
	}

	/**
	 * 读取[04 Input Registers 3x]类型 模拟量数据
	 * 
	 * @param slaveId
	 *            slaveId
	 * @param offset
	 *            位置
	 * @param dataType
	 *            数据类型,来自com.serotonin.modbus4j.code.DataType
	 * @return 返回结果
	 * @throws ModbusTransportException
	 *             异常
	 * @throws ErrorResponseException
	 *             异常
	 * @throws ModbusInitException
	 *             异常
	 */
	public static Number readInputRegisters(int slaveId, int offset, int dataType)
			throws ModbusTransportException, ErrorResponseException, ModbusInitException {
		// 04 Input Registers类型数据读取
		BaseLocator<Number> loc = BaseLocator.inputRegister(slaveId, offset, dataType);
		Number value = getMaster().getValue(loc);
		return value;
	}

	/**
	 * 批量读取使用方法
	 * 
	 * @throws ModbusTransportException
	 * @throws ErrorResponseException
	 * @throws ModbusInitException
	 */
	public static void batchRead() throws ModbusTransportException, ErrorResponseException, ModbusInitException {

		BatchRead<Integer> batch = new BatchRead<Integer>();

		batch.addLocator(0, BaseLocator.holdingRegister(1, 1, DataType.FOUR_BYTE_FLOAT));
		batch.addLocator(1, BaseLocator.inputStatus(1, 0));

		ModbusMaster master = getMaster();

		batch.setContiguousRequests(false);
		BatchResults<Integer> results = master.send(batch);
		System.out.println(results.getValue(0));
		System.out.println(results.getValue(1));
	}

	/**
	 * 测试
	 * 
	 * @param args
	 */
	public static void main(String[] args) {
		try {
			// 01测试
			Boolean v011 = readCoilStatus(1, 0);
			Boolean v012 = readCoilStatus(1, 1);
			Boolean v013 = readCoilStatus(1, 6);
			System.out.println("v011:" + v011);
			System.out.println("v012:" + v012);
			System.out.println("v013:" + v013);
			// 02测试
			Boolean v021 = readInputStatus(1, 0);
			Boolean v022 = readInputStatus(1, 1);
			Boolean v023 = readInputStatus(1, 2);
			System.out.println("v021:" + v021);
			System.out.println("v022:" + v022);
			System.out.println("v023:" + v023);

			// 03测试
			Number v031 = readHoldingRegister(1, 1, DataType.FOUR_BYTE_FLOAT);// 注意,float
			Number v032 = readHoldingRegister(1, 3, DataType.FOUR_BYTE_FLOAT);// 同上
			System.out.println("v031:" + v031);
			System.out.println("v032:" + v032);

			// 04测试
			Number v041 = readInputRegisters(1, 0, DataType.FOUR_BYTE_FLOAT);//
			Number v042 = readInputRegisters(1, 2, DataType.FOUR_BYTE_FLOAT);//
			System.out.println("v041:" + v041);
			System.out.println("v042:" + v042);
			// 批量读取
			batchRead();

		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

package com.tcb.modbus;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

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.WriteCoilRequest;
import com.serotonin.modbus4j.msg.WriteCoilResponse;
import com.serotonin.modbus4j.msg.WriteCoilsRequest;
import com.serotonin.modbus4j.msg.WriteCoilsResponse;
import com.serotonin.modbus4j.msg.WriteRegisterRequest;
import com.serotonin.modbus4j.msg.WriteRegisterResponse;
import com.serotonin.modbus4j.msg.WriteRegistersRequest;

/**
 * modbus4j写入数据
 * 
 * @author xq
 *
 */
public class Modbus4jWriteUtils {
	static Log log = LogFactory.getLog(Modbus4jWriteUtils.class);
	/**
	 * 工厂。
	 */
	static ModbusFactory modbusFactory;
	static {
		if (modbusFactory == null) {
			modbusFactory = new ModbusFactory();
		}
	}

	/**
	 * 获取tcpMaster
	 * 
	 * @return
	 * @throws ModbusInitException
	 */
	public static ModbusMaster getMaster() throws ModbusInitException {
		IpParameters params = new IpParameters();
		params.setHost("localhost");
		params.setPort(502);

		ModbusMaster tcpMaster = modbusFactory.createTcpMaster(params, false);
		tcpMaster.init();

		return tcpMaster;
	}

	/**
	 * 写 [01 Coil Status(0x)]写一个 function ID = 5
	 * 
	 * @param slaveId
	 *            slave的ID
	 * @param writeOffset
	 *            位置
	 * @param writeValue
	 *            值
	 * @return 是否写入成功
	 * @throws ModbusTransportException
	 * @throws ModbusInitException
	 */
	public static boolean writeCoil(int slaveId, int writeOffset, boolean writeValue)
			throws ModbusTransportException, ModbusInitException {
		// 获取master
		ModbusMaster tcpMaster = getMaster();
		// 创建请求
		WriteCoilRequest request = new WriteCoilRequest(slaveId, writeOffset, writeValue);
		// 发送请求并获取响应对象
		WriteCoilResponse response = (WriteCoilResponse) tcpMaster.send(request);
		if (response.isException()) {
			return false;
		} else {
			return true;
		}
	}

	/**
	 * 写[01 Coil Status(0x)] 写多个 function ID = 15
	 * 
	 * @param slaveId
	 *            slaveId
	 * @param startOffset
	 *            开始位置
	 * @param bdata
	 *            写入的数据
	 * @return 是否写入成功
	 * @throws ModbusTransportException
	 * @throws ModbusInitException
	 */
	public static boolean writeCoils(int slaveId, int startOffset, boolean[] bdata)
			throws ModbusTransportException, ModbusInitException {
		// 获取master
		ModbusMaster tcpMaster = getMaster();
		// 创建请求
		WriteCoilsRequest request = new WriteCoilsRequest(slaveId, startOffset, bdata);
		// 发送请求并获取响应对象
		WriteCoilsResponse response = (WriteCoilsResponse) tcpMaster.send(request);
		if (response.isException()) {
			return false;
		} else {
			return true;
		}

	}

	/***
	 * 写[03 Holding Register(4x)] 写一个 function ID = 6
	 * 
	 * @param slaveId
	 * @param writeOffset
	 * @param writeValue
	 * @return
	 * @throws ModbusTransportException
	 * @throws ModbusInitException
	 */
	public static boolean writeRegister(int slaveId, int writeOffset, short writeValue)
			throws ModbusTransportException, ModbusInitException {
		// 获取master
		ModbusMaster tcpMaster = getMaster();
		// 创建请求对象
		WriteRegisterRequest request = new WriteRegisterRequest(slaveId, writeOffset, writeValue);
		WriteRegisterResponse response = (WriteRegisterResponse) tcpMaster.send(request);
		if (response.isException()) {
			log.error(response.getExceptionMessage());
			return false;
		} else {
			return true;
		}

	}

	/**
	 * 
	 * 写入[03 Holding Register(4x)]写多个 function ID=16
	 * 
	 * @param slaveId
	 *            modbus的slaveID
	 * @param startOffset
	 *            起始位置偏移量值
	 * @param sdata
	 *            写入的数据
	 * @return 返回是否写入成功
	 * @throws ModbusTransportException
	 * @throws ModbusInitException
	 */
	public static boolean writeRegisters(int slaveId, int startOffset, short[] sdata)
			throws ModbusTransportException, ModbusInitException {
		// 获取master
		ModbusMaster tcpMaster = getMaster();
		// 创建请求对象
		WriteRegistersRequest request = new WriteRegistersRequest(slaveId, startOffset, sdata);
		// 发送请求并获取响应对象
		ModbusResponse response = tcpMaster.send(request);
		if (response.isException()) {
			log.error(response.getExceptionMessage());
			return false;
		} else {
			return true;
		}
	}

	/**
	 * 写入数字类型的模拟量（如:写入Float类型的模拟量、Double类型模拟量、整数类型Short、Integer、Long）
	 * 
	 * @param slaveId
	 * @param offset
	 * @param value
	 *            写入值,Number的子类,例如写入Float浮点类型,Double双精度类型,以及整型short,int,long
	 * @param registerCount
	 *            ,com.serotonin.modbus4j.code.DataType
	 * @throws ModbusTransportException
	 * @throws ErrorResponseException
	 * @throws ModbusInitException
	 */
	public static void writeHoldingRegister(int slaveId, int offset, Number value, int dataType)
			throws ModbusTransportException, ErrorResponseException, ModbusInitException {
		// 获取master
		ModbusMaster tcpMaster = getMaster();
		// 类型
		BaseLocator<Number> locator = BaseLocator.holdingRegister(slaveId, offset, dataType);
		tcpMaster.setValue(locator, value);
	}

	public static void main(String[] args) {
		try {
			//@formatter:off
			// 测试01
//			boolean t01 = writeCoil(1, 0, true);
//			System.out.println("T01:" + t01);

			// 测试02
//			boolean t02 = writeCoils(1, 0, new boolean[] { true, false, true });
//			System.out.println("T02:" + t02);

			// 测试03
//			short v = -3;
//			boolean t03 = writeRegister(1, 0, v);
//			System.out.println("T03:" + t03);
			// 测试04
//			boolean t04 = writeRegisters(1, 0, new short[] { -3, 3, 9 });
//			System.out.println("t04:" + t04);
			//写模拟量
			writeHoldingRegister(1,0, 10.1f, DataType.FOUR_BYTE_FLOAT);
			
			//@formatter:on
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

}

<dependency>
		<groupId>com.digitalpetri.modbus</groupId>
		<artifactId>modbus-master-tcp</artifactId>
		<version>1.1.0</version>
	</dependency>

package com.ioufev;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;

import com.digitalpetri.modbus.codec.Modbus;
import com.digitalpetri.modbus.master.ModbusTcpMaster;
import com.digitalpetri.modbus.master.ModbusTcpMasterConfig;
import com.digitalpetri.modbus.requests.ReadCoilsRequest;
import com.digitalpetri.modbus.requests.ReadDiscreteInputsRequest;
import com.digitalpetri.modbus.requests.ReadHoldingRegistersRequest;
import com.digitalpetri.modbus.requests.ReadInputRegistersRequest;
import com.digitalpetri.modbus.responses.ReadCoilsResponse;
import com.digitalpetri.modbus.responses.ReadDiscreteInputsResponse;
import com.digitalpetri.modbus.responses.ReadHoldingRegistersResponse;
import com.digitalpetri.modbus.responses.ReadInputRegistersResponse;

import io.netty.buffer.ByteBuf;
import io.netty.util.ReferenceCountUtil;

/***
 * modbus TCP协议Java通讯读取例子
 *
 *
 */
public class ModbusMasterTCPDemo {

    static ModbusTcpMaster master;

    /**
     * 获取TCP协议的Master
     *
     * @return
     */
    public static void initModbusTcpMaster() {
        if (master == null) {
            // 创建配置
            ModbusTcpMasterConfig config = new ModbusTcpMasterConfig.Builder("localhost").setPort(502).build();
            master = new ModbusTcpMaster(config);
        }
    }

    /***
     * 释放资源
     */
    public static void release() {
        if (master != null) {
            master.disconnect();
        }
        Modbus.releaseSharedResources();
    }

    /**
     * 读取Coils开关量
     *
     * @param address
     *            寄存器开始地址
     * @param quantity
     *            数量
     * @param unitId
     *            ID
     * @return 读取值
     * @throws InterruptedException
     *             异常
     * @throws ExecutionException
     *             异常
     */
    public static Boolean readCoils(int address, int quantity, int unitId)
            throws InterruptedException, ExecutionException {
        Boolean result = null;
        CompletableFuture<ReadCoilsResponse> future = master.sendRequest(new ReadCoilsRequest(address, quantity),
                unitId);
        ReadCoilsResponse readCoilsResponse = future.get();// 工具类做的同步返回.实际使用推荐结合业务进行异步处理
        if (readCoilsResponse != null) {
            ByteBuf buf = readCoilsResponse.getCoilStatus();
            result = buf.readBoolean();
            ReferenceCountUtil.release(readCoilsResponse);
        }
        return result;
    }

    /**
     * 读取readDiscreteInputs开关量
     *
     * @param address
     *            寄存器开始地址
     * @param quantity
     *            数量
     * @param unitId
     *            ID
     * @return 读取值
     * @throws InterruptedException
     *             异常
     * @throws ExecutionException
     *             异常
     */
    public static Boolean readDiscreteInputs(int address, int quantity, int unitId)
            throws InterruptedException, ExecutionException {
        Boolean result = null;
        CompletableFuture<ReadDiscreteInputsResponse> future = master
                .sendRequest(new ReadDiscreteInputsRequest(address, quantity), unitId);
        ReadDiscreteInputsResponse discreteInputsResponse = future.get();// 工具类做的同步返回.实际使用推荐结合业务进行异步处理
        if (discreteInputsResponse != null) {
            ByteBuf buf = discreteInputsResponse.getInputStatus();
            result = buf.readBoolean();
            ReferenceCountUtil.release(discreteInputsResponse);
        }
        return result;
    }

    /**
     * 读取HoldingRegister数据
     *
     * @param address
     *            寄存器地址
     * @param quantity
     *            寄存器数量
     * @param unitId
     *            id
     * @return 读取结果
     * @throws InterruptedException
     *             异常
     * @throws ExecutionException
     *             异常
     */
    public static Number readHoldingRegisters(int address, int quantity, int unitId)
            throws InterruptedException, ExecutionException {
        Number result = null;
        CompletableFuture<ReadHoldingRegistersResponse> future = master
                .sendRequest(new ReadHoldingRegistersRequest(address, quantity), unitId);
        ReadHoldingRegistersResponse readHoldingRegistersResponse = future.get();// 工具类做的同步返回.实际使用推荐结合业务进行异步处理
        if (readHoldingRegistersResponse != null) {
            ByteBuf buf = readHoldingRegistersResponse.getRegisters();
            result = buf.readFloat();
            ReferenceCountUtil.release(readHoldingRegistersResponse);
        }
        return result;
    }

    /**
     * 读取InputRegisters模拟量数据
     *
     * @param address
     *            寄存器开始地址
     * @param quantity
     *            数量
     * @param unitId
     *            ID
     * @return 读取值
     * @throws InterruptedException
     *             异常
     * @throws ExecutionException
     *             异常
     */
    public static Number readInputRegisters(int address, int quantity, int unitId)
            throws InterruptedException, ExecutionException {
        Number result = null;
        CompletableFuture<ReadInputRegistersResponse> future = master
                .sendRequest(new ReadInputRegistersRequest(address, quantity), unitId);
        ReadInputRegistersResponse readInputRegistersResponse = future.get();// 工具类做的同步返回.实际使用推荐结合业务进行异步处理
        if (readInputRegistersResponse != null) {
            ByteBuf buf = readInputRegistersResponse.getRegisters();
            result = buf.readDouble();
            ReferenceCountUtil.release(readInputRegistersResponse);
        }
        return result;
    }

    public static void main(String[] args) {
        try {
            // 初始化资源
            initModbusTcpMaster();

            // 执行操作

            // 读取开关量
            System.out.println(readCoils(0, 1, 1));
            System.out.println(readDiscreteInputs(0, 1, 1));
            System.out.println(readDiscreteInputs(1, 1, 1));

            // 读取模拟量
            System.out.println(readHoldingRegisters(0, 2, 1));
            System.out.println(readHoldingRegisters(2, 2, 1));
            System.out.println(readHoldingRegisters(4, 2, 1));
            System.out.println(readInputRegisters(2, 4, 1));
            System.out.println(readInputRegisters(6, 4, 1));

            // 释放资源
            release();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

// 发送单个寄存器数据，一般是无符号16位值：比如10
master.sendRequest(new WriteSingleRegisterRequest(address, value), unitId);

// float类型转字节数组
byte[] bytes = float2bytes(values);
// 转netty需要的字节类型
ByteBuf byteBuf = Unpooled.wrappedBuffer(bytes);

// 发送多个寄存器数据，数据类型由quantity决定，2是float类型，4是double类型
master.sendRequest(new WriteMultipleRegistersRequest(address,quantity,byteBuf), unitId);