Strange 'WriteFile' Freezing problem

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5 total messages Started by Ramy Thu, 20 Jul 2006 16:49

#3319

Author: Ramy
Date: Thu, 20 Jul 2006 16:49

17 lines
1313 bytes

Please Help, I'm having a very strange problem, sometimes my 
application is "Freezing" in the following command - 

WriteFile( hndl, TxBuff, MessageLen, &written, NULL ); 

(sending data through RS-232 port)

sometimes it's happening after 15 seconds, and sometimes after 2
minutes.... I checked the command parameters and they all looks
OK, I compared the command parameters (hndl, TxBuff...) when the
command works OK, and when it's freezing, and they looks exactly 
the same..... what can be the problem ?? 

Thanks! 

Ramy.

Re: Strange 'WriteFile' Freezing problem

#3320

Author: Remy Lebeau (TeamB)
Date: Thu, 20 Jul 2006 19:12

17 lines
1446 bytes

"Ramy" <Ramy@NoMail.com> wrote in message
news:44bfb418$1@newsgroups.borland.com...

> Please Help, I'm having a very strange problem, sometimes
> my application is "Freezing" in the following command -
>
> WriteFile( hndl, TxBuff, MessageLen, &written, NULL );
>
> (sending data through RS-232 port)

How much data are you actually sending? What kind of device is on the other
end of the port?  What kind of timeouts are you using?  Have you considered
using Overlapped I/O with the port yet?


Gambit

Re: Strange 'WriteFile' Freezing problem

#3328

Author: Ramy
Date: Sun, 23 Jul 2006 11:24

28 lines
1607 bytes


Hi, the timeouts that I use are the following - 

read_timeout.ReadIntervalTimeout         = 0;  
read_timeout.ReadTotalTimeoutMultiplier  = 150; 
read_timeout.ReadTotalTimeoutConstant    = 150; 
read_timeout.WriteTotalTimeoutMultiplier = 0;  
read_timeout.WriteTotalTimeoutConstant   = 150; 

I asked the WriteFile command to send 8 bytes, and the size of
my TxBuff[] is 250 bytes.

Any Idea ? 

"using Overlapped I/O with the port"

What does it do? do you have an example? is it complicate?

Thanks!



>How much data are you actually sending? What kind of device is on the other
>end of the port?  What kind of timeouts are you using?  Have you considered
>using Overlapped I/O with the port yet?
>
>Gambit

Re: Strange 'WriteFile' Freezing problem

#3329

Author: Ramy Ramy
Date: Sun, 23 Jul 2006 11:26

8 lines
1154 bytes

Sorry the timeouts are - 

read_timeout.ReadIntervalTimeout         = 0;  
read_timeout.ReadTotalTimeoutMultiplier  = 0; 
read_timeout.ReadTotalTimeoutConstant    = 150; 
read_timeout.WriteTotalTimeoutMultiplier = 0;  
read_timeout.WriteTotalTimeoutConstant   = 150;

Re: Strange 'WriteFile' Freezing problem

#3186

Author: Remy Lebeau (TeamB)
Date: Sun, 23 Jul 2006 19:00

39 lines
2097 bytes

"Ramy" <Ramy@NoMail.com> wrote in message
news:44c35c6a$1@newsgroups.borland.com...

> Hi, the timeouts that I use are the following -

These are the timeouts that I use:

    read_timeout.ReadIntervalTimeout = 0;
    read_timeout.ReadTotalTimeoutMultiplier = 5;
    read_timeout.ReadTotalTimeoutConstant = 5000;
    read_timeout.WriteTotalTimeoutMultiplier = 5;
    read_timeout.WriteTotalTimeoutConstant = 1000;

> I asked the WriteFile command to send 8 bytes, and the size of my TxBuff[]
is 250 bytes.

What buffer sizes are you specifying in SetupComm()?  What DBC values are
you specifying in SetCommState()?

> Any Idea ?

You did not answer my earlier question:

    "What kind of device is on the other end of the port?

If the device is having problems reading, and you are using any kind of flow
control, that might explain why your writing is freezing periodically.

> "using Overlapped I/O with the port"
>
> What does it do? do you have an example? is it complicate?

    Overlapped Operations

http://msdn.microsoft.com/library/en-us/devio/base/overlapped_operations.asp


Gambit

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