Date: Sat, 20 Feb 1999 20:44:44 -0600 (CST) From: Fred Gee <gee2@oldzoom.bga.com> To: freebsd-isp@FreeBSD.ORG Subject: Re: DPT's Storage Manager and FreeBSD Message-ID: <199902210244.UAA19502@oldzoom.bga.com>
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I haven't done this recently, but it was easy when we did it. Take the LED voltage, and apply it to a serial line driver input, on carrier detect on a port. We then hacked a getty to run our program rather than login. It may not even been more than a code segment we stole from getty source, I really don't remember. It's been a number of years, and we didn't use it much. We also had a external relay triggered by raising (or dropping) DTR, driving a 5v relay via some generic open collector driver of some sort. All very easy to construct, and very reliable. We used the output to reboot CSU's and other hardware remotely. We took the 5v relay to switch 12v to a larger contactor or relay (depending on the load). To trigger a DTR transition I think we hacked tip or cu. If you use expect, you may not even have to hack anything. Also, if you want to skip the external line driver circuit, you can wire the LED input directly to your serial card (if you know how) since the LED's are usually on 5v power. If you remove the LED you may need to replace it with a pull-down resistor, depending on what is driving it. If you don't remove it, you will need to tap the circuit before the LED's current limiting resistor, otherwise you won't get 5v, you will get a volt or two and not drive the input. You can jumper the current limiting resistor, but it should work with it in. Since this is something I need to do as well, now that you have reminded me of the need, I'll come up with something and follow up with the method and results. Should be a simple thing, take less time to do it than get DPT to write a driver (unless they have something already). George On Fri, 19 Feb 1999, Karl Pielorz wrote: > > > spork wrote: > > > > Is there any way to tell that the DPT has lost a disk without physically > > seeing the blinking lights or hearing the piercing siren? I have one of > > these about to be shipped out to a colo, and I have no idea how I'm going > > to tell if the thing needs attention. > > > > I suppose I could mount the speaker external and hope it annoys someone > > enough that they'll call the number on the cage, but... > > Or you could tie the bleeper to the Carrier Detect, or some other line on a > spare serial or Parallel port... We've toyed with doing that here, but not > gotten round to it (and we can hear the bleeper from our offices :) > > You then run a daemon on the system that checks to see if the connection is > high, or low... > > If you are going to take this route - take care, don't just hook it up :-) - > Research first, or you could damage the port / DPT... > > -Kp > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message
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