Date: Wed, 17 Nov 2004 09:47:06 +0200 From: Danny Braniss <danny@cs.huji.ac.il> To: "Daniel O'Connor" <doconnor@gsoft.com.au> Cc: freebsd-hackers@freebsd.org Subject: Re: Userland access to modem control lines? Message-ID: <20041117074707.4637043D55@mx1.FreeBSD.org> In-Reply-To: Message from "Daniel O'Connor" <doconnor@gsoft.com.au> <200411171719.16370.doconnor@gsoft.com.au>
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> --nextPart12368324.QZVX1XDbdm > Content-Type: text/plain; > charset="us-ascii" > Content-Transfer-Encoding: quoted-printable > Content-Disposition: inline > > Hi, > Does anyone know of a way to manipulate the modem control lines from userla= > nd? > SVR4 has termiox and friends but I can't see an equivalent for FreeBSD. > > The reason I ask is I am trying to talk to an RS485 bus - it is half duplex= > =20 > and the protocol converter uses RTS to control the data direction. > > I have a kernel driver which handles this but it has it's limitations (eg=20 > takes over the port and boot up, only usable on certain devices). > > I'm going to make it a line discipline eventually, but this was a stepping= > =20 > stone. > see /usr/include/sys/ttycom.h and TIOCMBIS, TIOCMBIC, TIOCMGET danny
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