Problem while reading the data from RS232 using Qextserialport

[sudheer168]

Hi Calhal and all,

Thanks for your reply.Actually that is not my problem, I am new to the threads concept. So I don't know how to use the threads in my program.Here I attached the source file. It consists of two processes. First one is Receiving the data from RS232 for every 1 millisecond. And another one is to insert the data into Database at the same time. So the process is breaking, because i haven't used the multi thread concept.

So any one can help me to solve the above problem.

With Regards,

Sudheer

[calhal]

Actually that is not my problem, I am new to the threads concept.

Maybe you're right. But please try to change

if(port->bytesAvailable())

if(port->bytesAvailable())

To copy to clipboard, switch view to plain text mode 

to this

if(port->bytesAvailable()>0)

if(port->bytesAvailable()>0)

To copy to clipboard, switch view to plain text mode 

and this

i = port->read(buff,numBytes);

i = port->read(buff,numBytes);

To copy to clipboard, switch view to plain text mode 

into this

if ( (i = port->read(buff,numBytes) <=0 ) return;

if ( (i = port->read(buff,numBytes) <=0 ) return;

To copy to clipboard, switch view to plain text mode 

And again why 1ms?

[wysota]

So the process is breaking, because i haven't used the multi thread concept.

You don't need multiple threads for that. Just increase the timer timeout as suggested - 100ms will be just as fine as 1ms. How fast is your serial port? How many bytes can it transmit during 1ms?

[sudheer168]

Hi Wysota and all,

Thanks for reply. The Hardware system is sending 4096 bytes per 1 millisecond. It is so fast data acquisition. So we need to receive the data of 4096 bytes and at the same time we need to insert into the Database. So 1 millisecond is not perfect time to receive and insert. If we used the Timer for receiving then some data has been missing. So for that problem the multi thread concept is better. I am new to threads. I would like to know how to create , use the threads as per our program (I attached the C++ and .h files). Help me to solve this problem.


With Regards,

Sudheer

[calhal]

The Hardware system is sending 4096 bytes per 1 millisecond

So you're trying to receive 4kB/ms with 115200baud port or I'm missing something?

[wysota]

If we used the Timer for receiving then some data has been missing.

Nothing would be missing, the data is buffered.

So for that problem the multi thread concept is better.

Of course you are aware of the fact that threads slow down your application, so you will be aquiring your data in a lower rate, right?

By the way, you want to transfer four megabytes of data per second? Some fast serial port you have there... 32 megabauds? Are you sure your calculations are correct?