本人在网上找了很多类似的例子，但是发送都报错。求问哪位大神遇到过这样的问题，或有更好的例子。跪求啊
使用的包
<dependency>
<groupId>com.infiniteautomation</groupId>
<artifactId>modbus4j</artifactId>
<version>3.0.3</version>
</dependency>
代码
package com.shop.utils.modbus;
import com.serotonin.modbus4j.ModbusFactory;
import com.serotonin.modbus4j.ModbusMaster;
import com.serotonin.modbus4j.exception.ModbusInitException;
import com.serotonin.modbus4j.exception.ModbusTransportException;
import com.serotonin.modbus4j.ip.IpParameters;
import com.serotonin.modbus4j.msg.*;
import com.serotonin.modbus4j.sero.util.queue.ByteQueue;
public class ReadAWriteUtils {
/**
* 批量写数据到保持寄存器
* @param ip 从站IP
* @param port modbus端口
* @param slaveId 从站ID
* @param start 起始地址偏移量
* @param values 待写数据
*/
public static void modbusWTCP(String ip, int port, int slaveId, int start, short[] values) {
ModbusFactory modbusFactory = new ModbusFactory();
// 设备ModbusTCP的Ip与端口，如果不设定端口则默认为502
IpParameters params = new IpParameters();
params.setHost(ip);
// 设置端口，默认502
if (502 != port) {
params.setPort(port);
}
ModbusMaster tcpMaster = null;
// 参数1：IP和端口信息 参数2：保持连接激活
tcpMaster = modbusFactory.createTcpMaster(params, true);
try {
tcpMaster.init();
System.out.println("=======初始化成功========");
} catch (ModbusInitException e) {
System.out.println("初始化异常");
}
try {
WriteRegistersRequest request = new WriteRegistersRequest(slaveId, start, values);
WriteRegistersResponse response = (WriteRegistersResponse) tcpMaster.send(request);
if (response.isException()){
System.out.println("Exception response: message=" + response.getExceptionMessage());
}else{
System.out.println("Success");
}
} catch (ModbusTransportException e) {
e.printStackTrace();
}
}
/**
* 读保持寄存器上的内容
* @param ip 从站IP
* @param port modbus端口
* @param start 起始地址偏移量
* @param readLenth 待读寄存器个数
* @return
*/
public static ByteQueue modbusTCP(String ip, int port, int start,int readLenth) {
ModbusFactory modbusFactory = new ModbusFactory();
// 设备ModbusTCP的Ip与端口，如果不设定端口则默认为502
IpParameters params = new IpParameters();
params.setHost(ip);
//设置端口，默认502
if(502!=port){
params.setPort(port);
}
ModbusMaster tcpMaster = null;
tcpMaster = modbusFactory.createTcpMaster(params, true);
try {
tcpMaster.init();
System.out.println("========初始化成功=======");
} catch (ModbusInitException e) {
e.printStackTrace();
return null;
}
ModbusRequest modbusRequest=null;
try {
//功能码03 读取保持寄存器的值
modbusRequest = new ReadInputRegistersRequest(1, start, readLenth);
} catch (ModbusTransportException e) {
e.printStackTrace();
}
ModbusResponse modbusResponse=null;
try {
modbusResponse = tcpMaster.send(modbusRequest);
} catch (ModbusTransportException e) {
e.printStackTrace();
}
ByteQueue byteQueue= new ByteQueue(1024);
modbusResponse.write(byteQueue);
System.out.println("功能码:"+modbusRequest.getFunctionCode());
System.out.println("从站地址:"+modbusRequest.getSlaveId());
System.out.println("收到的响应信息大小:"+byteQueue.size());
System.out.println("收到的响应信息值:"+byteQueue);
return byteQueue;
}
public static void main(String[] args){
modbusTCP("192.168.11.51",502,0x00,2);
}
}
报错信息：
========初始化成功=======
17:58:06.566 [main] DEBUG com.serotonin.modbus4j.ip.tcp.TcpMaster - Encap Request: 00 00 00 00 00 06 01 04 00 00 00 02
17:58:06.571 [main] DEBUG com.serotonin.modbus4j.ip.tcp.TcpMaster - Sending on port: 502
17:58:08.097 [main] DEBUG com.serotonin.modbus4j.ip.tcp.TcpMaster - Exception: request=XaMessage [transactionId=0, message=ReadInputRegistersRequest [slaveId=1, getFunctionCode()=4, toString()=ReadNumericRequest [startOffset=0, numberOfRegisters=2]]] request=XaMessage [transactionId=0, message=ReadInputRegistersRequest [slaveId=1, getFunctionCode()=4, toString()=ReadNumericRequest [startOffset=0, numberOfRegisters=2]]]
17:58:08.097 [main] DEBUG com.serotonin.modbus4j.ip.tcp.TcpMaster - KeepAlive - reconnect!
17:58:08.097 [main] DEBUG com.serotonin.modbus4j.ip.tcp.TcpMaster - Modbus4J: Keep-alive connection may have been reset. Attempting to re-open.
com.serotonin.modbus4j.exception.ModbusTransportException: com.serotonin.modbus4j.sero.messaging.TimeoutException: request=XaMessage [transactionId=0, message=ReadInputRegistersRequest [slaveId=1, getFunctionCode()=4, toString()=ReadNumericRequest [startOffset=0, numberOfRegisters=2]]]
at com.serotonin.modbus4j.ip.tcp.TcpMaster.sendImpl(TcpMaster.java:168)
at com.serotonin.modbus4j.ModbusMaster.send(ModbusMaster.java:105)
at com.shop.utils.modbus.ReadAWriteUtils.modbusTCP(ReadAWriteUtils.java:88)
at com.shop.utils.modbus.ReadAWriteUtils.main(ReadAWriteUtils.java:103)
Caused by: com.serotonin.modbus4j.sero.messaging.TimeoutException: request=XaMessage [transactionId=0, message=ReadInputRegistersRequest [slaveId=1, getFunctionCode()=4, toString()=ReadNumericRequest [startOffset=0, numberOfRegisters=2]]]
at com.serotonin.modbus4j.sero.messaging.MessageControl.send(MessageControl.java:140)
at com.serotonin.modbus4j.sero.messaging.MessageControl.send(MessageControl.java:105)
at com.serotonin.modbus4j.ip.tcp.TcpMaster.sendImpl(TcpMaster.java:154)
... 3 more
Exception in thread "main" java.lang.NullPointerException
17:58:09.600 [main] DEBUG com.serotonin.modbus4j.ip.tcp.TcpMaster - Exception: request=XaMessage [transactionId=0, message=ReadInputRegistersRequest [slaveId=1, getFunctionCode()=4, toString()=ReadNumericRequest [startOffset=0, numberOfRegisters=2]]] request=XaMessage [transactionId=0, message=ReadInputRegistersRequest [slaveId=1, getFunctionCode()=4, toString()=ReadNumericRequest [startOffset=0, numberOfRegisters=2]]]
at com.shop.utils.modbus.ReadAWriteUtils.modbusTCP(ReadAWriteUtils.java:93)
at com.shop.utils.modbus.ReadAWriteUtils.main(ReadAWriteUtils.java:103)
Disconnected from the target VM, address: '127.0.0.1:49432', transport: 'socket'
Process finished with exit code 1
