Date: Mon, 10 Jul 2000 21:19:08 +0200 From: Olaf Hoyer <inferno@nightfire.de> To: Brian Handy <handy@isass0.solar.isas.ac.jp> Cc: freebsd-hardware@FreeBSD.ORG Subject: Re: Serial I/O thruput Message-ID: <396A21AC.A43F233E@nightfire.de> References: <Pine.OSF.4.05.10007101143590.24754-100000@isass0.solar.isas.ac.jp>
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> This time it's more dumb questions though. I want to talk to three CCD > cameras, and I'd like to download data from these cameras just about as > fast as I can. The communications bus is TBD; it could be serial > connections, parallel ports, heck, could even be USB maybe. (Or some > other method I haven't been made aware of yet.) I had originally thought > rather simplistically about using RS-232, since the board I'm looking at > has (I think) 4 serial ports. > > However...I'm not sure how fast I can push data into the motherboard over > these ports. I don't have any hardware yet (that's what the proposal is > for), so I can't really benchmark anything. Is multiple serial ports (or > a multi-port serial card) a silly idea for this? Any suggestions, and > what sort of transfer rates I can expect? The only complicating factor is > I have to talk to three cameras, each of which is [baseline] capable of > generating 4MB of data every 10 seconds. Hi! Well, the standard 16550 FIFO is capable of shovelling about 115200 bps. There are better chips available, that shall be able to do more than (IIRC, 8 times) that value. YOu need some special drivers for that. RS 422 or so come to mind, but you will need special gear for that. I'd check that out if ya need to. Cyclades comes to mind... They are working hard on native FreeBSD drivers, and introduced some new cards yet, as I heard on Linuxtag 2000 in Stuttgart. And they want to cooperate with the FreeBSD driver coders for those cards. Regards Olaf Hoyer To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message
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