Date: Mon, 22 Sep 1997 08:50:26 +0930 From: Greg Lehey <grog@lemis.com> To: Jonathan Chen <jonc@pinnacle.co.nz> Cc: FreeBSD Questions <questions@FreeBSD.org> Subject: Re: Serial Port Message-ID: <19970922085026.35506@lemis.com> In-Reply-To: <Pine.SGI.3.96.970922091901.16205C-100000@tui.pinnacle.co.nz>; from Jonathan Chen on Mon, Sep 22, 1997 at 09:22:40AM %2B1200 References: <199709191750.KAA00710@celebris.tddhome> <Pine.SGI.3.96.970922091901.16205C-100000@tui.pinnacle.co.nz>
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On Mon, Sep 22, 1997 at 09:22:40AM +1200, Jonathan Chen wrote: > On Fri, 19 Sep 1997, Thomas Dean wrote: > >> I am attempting to use a serial port to talk to a Gramin GPS 45XL. >> >> I can talk to the device, read and write data. The results make >> sense. >> >> I am using /dev/cuaa0. >> >> I have one problem. The communications with the device are not >> reliable. I execute an application to send the device a command and >> read the results. It works. I issue the same command again and it >> hangs. Actually, I use select() and it times out after 15 seconds. >> Increasing the timeout to 100 seconds does not change things. > > How about enabling h/w flow-control with the tcsetattr() call? If I > remember correctly the flags you use are CCTS_OFLOW and CRTS_IFLOW > (check out the man entry). Unfortunately, the serial interface has only Ground, TxD and RxD. It would be interesting to see if it understands XON/XOFF, though. Greg
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