springboot 实现modbus rtu 协议

Boot可以通过整合jlibmodbus库来实现modbus RTU协议。具体实现步骤如下：
1. 在pom.xml文件中添加jlibmodbus依赖：

<dependency>
    <groupId>com.intelligt.modbus</groupId>
    <artifactId>jlibmodbus</artifactId>
    <version>1.2.0</version>
</dependency>

2. 创建ModbusMaster类，用于连接modbus从站并发送/接收数据：

public class ModbusMaster {
    private ModbusMasterTcpClient client;
    private int slaveId;

    public ModbusMaster(String host, int port, int slaveId) {
        this.client = new ModbusMasterTcpClient(host, port);
        this.slaveId = slaveId;
    }

    public void connect() throws Exception {
        client.connect();
    }

    public void disconnect() throws Exception {
        client.disconnect();
    }

    public boolean isConnected() {
        return client.isConnected();
    }

    public void writeSingleCoil(int address, boolean value) throws Exception {
        client.writeSingleCoil(slaveId, address, value);
    }

    public void writeSingleRegister(int address, int value) throws Exception {
        client.writeSingleRegister(slaveId, address, value);
    }

    public boolean[] readCoils(int address, int quantity) throws Exception {
        return client.readCoils(slaveId, address, quantity);
    }

    public int[] readHoldingRegisters(int address, int quantity) throws Exception {
        return client.readHoldingRegisters(slaveId, address, quantity);
    }
}

3. 创建ModbusConfig类，用于配置modbus连接参数：

@Configuration
public class ModbusConfig {
    @Value("${modbus.host}")
    private String host;

    @Value("${modbus.port}")
    private int port;

    @Value("${modbus.slaveId}")
    private int slaveId;

    @Bean
    public ModbusMaster modbusMaster() {
        return new ModbusMaster(host, port, slaveId);
    }
}

4. 在application.properties文件中配置modbus连接参数：

modbus.host=127.0.0.1
modbus.port=502
modbus.slaveId=1

5. 在需要使用modbus的地方注入ModbusMaster类，并调用相应的方法即可：

@Autowired
private ModbusMaster modbusMaster;

public void writeSingleCoil() throws Exception {
    modbusMaster.writeSingleCoil(0, true);
}

public boolean[] readCoils() throws Exception {
    return modbusMaster.readCoils(0, 10);
}