net.wimpi.modbus.ModbusIOException: I/O exception - failed to read

Question

I'm using serial Modbus (jamod) to read data from device. I'm able to connect to the device but unable to read data from the register.

Here is my code:

public class Serial {

    static SerialConnection connection = null;
    SerialParameters params;
    ModbusSerialTransaction transaction = null;

    ReadMultipleRegistersRequest holdingRequest = null;
    ReadMultipleRegistersResponse holdingResponse = null;

    public void getData() {
        try {
            ModbusCoupler.getReference().setUnitID(1);
            params = new SerialParameters();
            params.setPortName("/dev/ttyS0");
            params.setBaudRate(9600);
            params.setDatabits(8);
            params.setEncoding(Modbus.SERIAL_ENCODING_RTU);
            params.setParity("None");
            params.setStopbits(1);
            params.setEcho(false);
            params.setReceiveTimeout(500);
            connection = new SerialConnection(params);
            connection.open();
            checkRegister(40257, 2);
            connection.close();

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

    public void registerData(int address, int count) {
        holdingRequest = new ReadMultipleRegistersRequest(address, count);
        holdingResponse = new ReadMultipleRegistersResponse();
        holdingRequest.setUnitID(130); // I tried with 1 and getting same error
        holdingRequest.setHeadless();
        holdingResponse = (ReadMultipleRegistersResponse) executeRequest(connection, holdingRequest);
        System.out.println("Response: " + holdingResponse);
    }

    private ModbusResponse executeRequest(SerialConnection connection, ModbusRequest request) {
        try {
            transaction = new ModbusSerialTransaction(connection);
            transaction.setRequest(request);
            Thread.sleep(500);
            transaction.execute(); // Error at this line
            return transaction.getResponse();
        } catch(Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}

I'm getting the following error at line transaction.execute():

net.wimpi.modbus.ModbusIOException: I/O exception - failed to read
    at net.wimpi.modbus.io.ModbusRTUTransport.readResponse(ModbusRTUTransport.java:163)
    at net.wimpi.modbus.io.ModbusSerialTransaction.execute(ModbusSerialTransaction.java:187)
    at Serial.executeRequest(Serial.java:279)
    at Serial.checkRegister(Serial.java:337)
    at Serial.getData(Serial.java:66)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.camel.component.bean.MethodInfo.invoke(MethodInfo.java:408)
    at org.apache.camel.component.bean.MethodInfo$1.doProceed(MethodInfo.java:279)
    at org.apache.camel.component.bean.MethodInfo$1.proceed(MethodInfo.java:252)
    at org.apache.camel.component.bean.BeanProcessor.process(BeanProcessor.java:177)
    at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:77)
    at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:460)
    at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
    at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:190)
    at org.apache.camel.component.timer.TimerConsumer.sendTimerExchange(TimerConsumer.java:165)
    at org.apache.camel.component.timer.TimerConsumer$1.run(TimerConsumer.java:73)
    at java.util.TimerThread.mainLoop(Timer.java:555)
    at java.util.TimerThread.run(Timer.java:505)

Any advice would be appreciated.

What is the device? What is the physical interface (RS-232, RS-422, something else?) Sounds like you are going to have to determine if the device is actually responding, which is down at the hardware level. — Jim Garrison, Jun 15 '16 at 05:50
It's an energy meter. I'm using RS-485 and Yes, the device is responding. — user2782405, Jun 15 '16 at 05:57
Hey! @user2782405 , Were you able to resolve this problem.. If Yes! then how. Actually I'm facing the same issue with same device.. — Kumar Anil Chaurasiya, May 17 '20 at 13:07
There was an issue with my embedded computer. For some reason, it couldn't recognize serial ports. When I switched to a different unit, it started working — user2782405, May 20 '20 at 14:24
@KumarAnilChaurasiya also, I remember opening serial port before running this code. But I don't remember the steps. Hope this helps! — user2782405, May 21 '20 at 07:36
@user2782405 , Can look into this once. let me know know if I am doing anything wrong. https://stackoverflow.com/questions/61852628/j2mod-i-o-exception-failed-to-read — Kumar Anil Chaurasiya, May 21 '20 at 15:18

net.wimpi.modbus.ModbusIOException: I/O exception - failed to read

0 Answers0