devc-ser8250 DTR problem

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Oleg Khamayko

devc-ser8250 DTR problem

Post by Oleg Khamayko » Tue Jun 06, 2006 10:34 am

Hi!

Our hardware works thru RS-232 ports. All RS232 lines are used.

There's a problem araised with devc-ser8250.

We've connected serial line analizer to the serial #1 port and run

stty < /dev/ser1

analizer's DTR lamp blinks! (DTR lowers for about 300ms(?) )

The same effect (analizer's DTR line blinks) when using
devctl(fd, DCMD_CHR_LINESTATUS, ..) C-function,
the program is like example#1 from devctl(...) C-function manpage
but calling only function "int check_RTS(int fd)" .

Q1: How can be checked a serial line status, not effecting the line signals
(the DTR)?

Q2: Is it possible to control DTR line (lower DTR forever, not for an
interval)?

Thanx
Oleg

Oleg Khamayko

Re: devc-ser8250 DTR problem

Post by Oleg Khamayko » Tue Jun 06, 2006 11:36 am

Q1: - Solved.

It is the close(fd) problem.

devc-ser8250 runs with +hupcl flag set by default -> on close(fd) DTR is
lowered for the default interval.

Today is 06.06.06 - maybe thats why...)))

Oleg Khamayko <olegax@mail.ru> wrote in message
news:e63lm5$kot$1@inn.qnx.com...
Hi!

Our hardware works thru RS-232 ports. All RS232 lines are used.

There's a problem araised with devc-ser8250.

We've connected serial line analizer to the serial #1 port and run

stty < /dev/ser1

analizer's DTR lamp blinks! (DTR lowers for about 300ms(?) )

The same effect (analizer's DTR line blinks) when using
devctl(fd, DCMD_CHR_LINESTATUS, ..) C-function,
the program is like example#1 from devctl(...) C-function manpage
but calling only function "int check_RTS(int fd)" .

Q1: How can be checked a serial line status, not effecting the line
signals
(the DTR)?

Q2: Is it possible to control DTR line (lower DTR forever, not for an
interval)?

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