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SubjectRe: [PATCH] Documentation about RS485 serial communications
Hi!

> Documentation about RS485 serial communications

I have seen hardware (kontron pmc-6l) that was capable of switching
between RS232, RS485 and one other standard by software.

Is such hw common? If so, should we have standard interface?

> + From user-level, RS485 configuration can be get/set using the previous
> + ioctls. For instance, to set RS485 you can use the following code:
> +
> + #include <linux/serial.h>
> +
> + /* Driver-specific ioctls: */
> + #define TIOCGRS485 0x542E
> + #define TIOCSRS485 0x542F
> +
> + /* Open your specific device (e.g., /dev/mydevice): */
> + int fd = open ("/dev/mydevice", O_RDWR);
> + if (fd < 0) {
> + /* Error handling. See errno. */
> + }
> +
> + struct serial_rs485 rs485conf;
> +
> + /* Set RS485 mode: */
> + rs485conf.flags |= SER_RS485_ENABLED;

IOW... is this supposed to switch electrical levels?

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html


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