Date: Fri, 19 May 2000 11:23:38 -0700 From: Mike Smith <msmith@freebsd.org> To: chip@chocobo.cx Cc: freebsd-small@freebsd.org Subject: Re: RS-485 on a PCM-4823 Message-ID: <200005191823.LAA09168@mass.cdrom.com> In-Reply-To: Your message of "Fri, 19 May 2000 13:29:12 EDT." <20000519132912.A74009@setzer.chocobo.cx>
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> I've got an Advantech PCM-4823 (single board computer with ethernet, > VGA, IDE, 486 etc) running FreeBSD 4.0-RELEASE, and am trying to use > the boards second serial port in RS-485 mode. Everything works fine > if I use one of the RS-232 ports with an RS-485 adapter connected to > it, but when I try to use the built in 485, nothing seems to get > received, but transmission works fine (I can see it from the other > end.) After a while, the kernel starts complaining on the console > about > /kernel: sio1: 1069 more tty-level buffer overflows (total 3735) > and continues doing this for a little while, ending with a total of > 12567 buffer overflows. > > Anyone using RS-485 successfully or have any idea what I'm doing > wrong? The tty-level buffer overflows suggest that you're not actually reading from the port - there's a heap of data queued ready for someone to read from sio0, but nobody is. -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-small" in the body of the message
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