J2Mod-I / O异常-读取失败

Question

我正在为我的项目使用J2Mod Java jar。我通过comport与设备连接，但是无法读取数据或将数据写入设备。两次尝试读取或向设备写入数据时都遇到相同的异常。每当使用QModMaster时，我都可以从设备读取数据。

连接代码-

SerialParameters parameters;
SerialConnection serialMaster;

try {
        parameters = new SerialParameters();

        parameters.setPortName((String) jComboBox4.getSelectedItem());
        //parameters.setCommPortId("/dev/ttyUSB1");
        parameters.setBaudRate(9600);
        parameters.setDatabits(8);
        parameters.setStopbits(1);
        parameters.setParity("none");
        // parameters.setEncoding("rtu");
        // parameters.setEcho(false);
        System.out.println("Connection Section" + parameters);
        serialMaster = new SerialConnection(parameters);

        serialMaster.open();
        System.out.println("Connection open :" + serialMaster.isOpen());

    } catch (Exception ex) {
        Logger.getLogger(TankIQ_Configurator.class.getName()).log(Level.SEVERE, null, ex);
    }

用于读取数据的代码-

ReadMultipleRegistersRequest readMultipleRegistersRequest;
ReadMultipleRegistersResponse readMultipleRegistersResponse;
ModbusSerialTransaction trans;    

trans = new ModbusSerialTransaction(serialMaster);

Register[] register = {simpleRegister1, simpleRegister2};

int unitid = 1; //the unit identifier we will be talking to
int ref = 50; //the reference, where to start reading from
int count = 2; //the count of IR's to read
int repeat = 1; //a loop for repeating the transaction

//4. Open the connection
try{
    //5. Prepare a request
    readMultipleRegistersRequest = new ReadMultipleRegistersRequest(50, 2);
    readMultipleRegistersRequest.setUnitID(unitid);
    readMultipleRegistersRequest.setHeadless();

    //6. Prepare a transaction
    trans = new ModbusSerialTransaction(serialMaster);
    trans.setRequest(readMultipleRegistersRequest);

    int k = 0;
    do {
        trans.setTransDelayMS(1000);
        trans.execute();
        readMultipleRegistersResponse = (ReadMultipleRegistersResponse) trans.getResponse();
        for (int n = 0; n < readMultipleRegistersResponse.getWordCount(); n++) {
            System.out.println("Word " + n + "=" + readMultipleRegistersResponse.getRegisterValue(n));
        }
        k++;
    } while (k < repeat);
    serialMaster.close();//8. Close the connection
} catch (Exception ex) {
    Logger.getLogger(WriteMultipleRegistersRequest.class.getName()).log(Level.SEVERE, null, ex);
}

Answer 1

谢谢！所有参与此问题的人。

现在，让我解释一下，为什么会出现此错误。

除unitid外，所有代码都可以使用。 unitid仅是从属地址。在我的情况下，从站地址为5。