Difference between qtalk and "echo & cat"

QNX Newsgroups (Archives) comp.os.qnx
1

Hi,

We’re having serial communication problem between QNX 6.2 and our hardware
device (RF Generator). When we try to use “echo” to send commands to the RF
and read the responds using “cat”, we will get some non-printable characters
occasionally. However, when we use “qtalk -m /dev/ser1”, we have no problem
at all, does anyone know if there’s any flow control done by qtalk
internally? The RF generator doesn’t support software or hardware flow
control.

Thanks

Roger

2

roger <rogeryung@engensys.com> wrote:

Hi,

We’re having serial communication problem between QNX 6.2 and our hardware
device (RF Generator). When we try to use “echo” to send commands to the RF
and read the responds using “cat”, we will get some non-printable characters
occasionally. However, when we use “qtalk -m /dev/ser1”, we have no problem
at all, does anyone know if there’s any flow control done by qtalk
internally? The RF generator doesn’t support software or hardware flow
control.

qtalk may set/change the baud rate.

And the getting of the non-printable characters also suggests baud rate
to me.

I would suggest trying a “stty < /dev/ser1” before running qtalk, then
doing so again while qtalk is using the port, and comparing the settings,
especially the baud rate.

-David

QNX Training Services
http://www.qnx.com/services/training/
Please followup in this newsgroup if you have further questions.