v3.0.3 modbus rtu not working stable

[Ilhan SEVEN]

Hi everyone,

I am on Beaglebone Black Angstrom Linux.

    struct timeval response_timeout;
    response_timeout.tv_sec = 0;
    response_timeout.tv_usec = 50000;
    entesPoller = modbus_new_rtu("/dev/ttyO4", 9600, 'N', 8, 1);
    modbus_rtu_set_serial_mode(entesPoller, MODBUS_RTU_RS485);
    modbus_set_slave(entesPoller, 2);
    modbus_set_debug(entesPoller, 1);
    modbus_set_response_timeout(entesPoller, &response_timeout);
    if(entesPoller == NULL) {
        qDebug() << "Unable to create EntesPoller modbus context";
    }else {
        connected = modbus_connect(entesPoller);
    }
    modbus_flush(entesPoller);

And every 5 seconds:

    if(connected == -1) {
        qDebug() << "Cannot connect to Entes";
    } else if(connected == 0) {
        qDebug() << "Values from Entes: ";
        modbus_read_registers(entesPoller, entesInformation::importEnergyLSBAddress, 4, entesRegisters);
        for(int i=0; i<4; i++) {
            qDebug() << entesRegisters[i];
        }
    }
    modbus_flush(entesPoller);

Read success rate is very very low. 

General error:

ERROR CRC received xxxx != CRC calculated xxxx

Second error

Connection timed out: Select

Third from time to time:

Waiting for a confirmation...

<00><3C><00><04><84><36><02><03><08><00><E0><00><00><00><53><00><00><8B><4C><02><03 bytes flashed,

Any ideas what can be the isse?

Thanks in advance,

Ilhan

[oldfaber]

Your response_timeout.tv_usec is too short.

Best regards
Fabio