[ts-7000] Re: ttyS0 linux serial buffer size

["kendwyer" <>]

Hi 

thanks for the replies, this helps a lot.

Ken

--- In  "Don W. Carr" <> wrote:
>
> With the read system call, there is NO guarantee that it will not return
> with less data when it is available. This depends on the device and
internal
> buffer sizes, etc. You should never write code that assumes you will
get all
> of the bytes you ask for, even if you are sure they have been sent.
It is
> your job to write a loop to handle this.
> 
> Here is some example code, but you also need to check for a return
value of
> -1 and handle that. Hope this helps
> 
> I also have some code for setting the baud rate and timeout if you
need it..
> 
> Don.
> 
> int rt_read_serial(int fd, void *data, int sz)
> {
>   int total_read = 0;
>   char *dp = (char *) data;
>   while (total_read < sz)
>   {
>     int n = read(fd, dp + total_read, sz - total_read);
>     if (n == 0)
>     {
>       // we timed out waiting for our characters.
>       return total_read;
>     }
>     total_read += n;
>   }
>   return total_read;
> }
> 
> 
> 
> On 12/19/06, kendwyer <> wrote:
> >
> >   Hi,
> >
> > I am using the TS-7260 system for my application. I have found that
> > the tty (at least ttyS0) will only read 4096 bytes as a defualt
> > maximum, when my user code executes the following, r =
> > read(ft,ser_databuf,4096);.
> >
> > When I change the code as follows:
> >
> > res1 = read(ft,ser_databuf,8192);
> >
> > I still only read 4096 bytes...
> >
> > How/where do I change the code to read greater than 4096?
> >
> > Thanks,
> > Ken
> >
> >  
> >
> 
> 
> 
> -- 
> Dr. Don W. Carr
> J. G. Montenegro 2258
> Guadalajara, Mexico
> +52-333-630-0704
> +52-333-836-4500 ext 2930
>




 
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