Re: file descriptor of a serial port

[jan.de.kruyf@gmail.com]

On Monday, August 20, 2018 at 9:26:57 PM UTC+2, Dmitry A. Kazakov wrote:
> On 2018-08-20 21:10, jan.....com wrote:
> > On Monday, August 20, 2018 at 6:36:31 PM UTC+2, Dmitry A. Kazakov wrote:
> >> On 2018-08-20 16:33, jan......com wrote:
> >>> On Monday, August 20, 2018 at 4:21:20 PM UTC+2, J-P. Rosen wrote:
> >>>> Le 20/08/2018 à 15:56, jan.....com a écrit :
> >>>>> Hallo,
> >>>>>
> >>>>> I try to set up a custom baudrate on a serial port, which I believe
> >>>>> is done with the C ioctl procedure.
> >>>>>
> >>>> GNAT.Serial_Communications has a Set procedure to set various
> >>>> parameters, including baud rate. No need to play with the low level.
> >>>>
> >>>> -- 
> >>>> J-P. Rosen
> >>>> Adalog
> >>>> 2 rue du Docteur Lombard, 92441 Issy-les-Moulineaux CEDEX
> >>>> Tel: +33 1 45 29 21 52, Fax: +33 1 45 29 25 00
> >>>> http://www.adalog.fr
> >>>
> >>> Pity, does not work.
> >>
> >> How do you know it does not? The call goes right to the OS, at least
> >> under Windows. There is little one could do wrong or differently to the
> >> GNAT implementation.
> >>
> >> Maybe the settings you are using are incorrect or the way you are
> >> reading from the port.
> 
> E.g. depending on the settings and how poorly the other party was 
> designed, which quite frequently quite poorly, you must be always 
> reading the next byte from the COM port in order to prevent deadlock. 
> Sometimes you have to read out all garbage before sending anything to 
> the other side etc.
> 
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de

Dmitry good morning to you,

I think you still misunderstand the requirement. I need a very non-standard baud-rate which Gnat does not cater for, most likely because Linux can only be persuaded by a big roundabout to have a non-standard baud rate on a port.

So I was hoping to test the big roundabout to see if it will work with the FTDI driver in Linux. If not I will have to write a complete new serial port driver based on the proprietary FDTI driver from the chip manufacturers.

Cheers,
j.