From owner-freebsd-hackers Mon Feb 5 01:50:01 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id BAA15115 for hackers-outgoing; Mon, 5 Feb 1996 01:50:01 -0800 (PST) Received: from hda.com (hda.com [199.232.40.182]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id BAA15106 for ; Mon, 5 Feb 1996 01:49:55 -0800 (PST) Received: (from dufault@localhost) by hda.com (8.6.11/8.6.9) id EAA13984; Mon, 5 Feb 1996 04:44:38 -0500 From: Peter Dufault Message-Id: <199602050944.EAA13984@hda.com> Subject: Re: Watchdog timer To: uhclem@nemesis.lonestar.org (Frank Durda IV) Date: Mon, 5 Feb 1996 04:44:37 -0500 (EST) Cc: hackers@freebsd.org In-Reply-To: from "Frank Durda IV" at Feb 4, 96 09:41:00 pm X-Mailer: ELM [version 2.4 PL24] Content-Type: text Sender: owner-hackers@freebsd.org Precedence: bulk > [18]This (the power cycling) would add significantly to the cost of the unit; > [18]consider a 15A relay and the extra wiring involved in terms of assembly > [18]cost. > Do any of the UPS vendors have auxiliary ports that will power cycle the unit? It seems as if they should. This would be appropriate for a small site with one critical machine on an UPS, and anyone needing this watch dog board will also have an UPS. For that matter, do any of the UPS vendors have a watchdog? That would make even more sense. Unimportant side note - the LED signal on a SCSI system will typically be SCSI busy, so a user daemon sending "test unit ready" will blink the light without reading off the disk . I missed a lot of this and started paying attention with Frank's clever idea, so this may already have been brought up and you are looking for low cost solutions: You can buy off the shelf watchdog boards. The only one I found in 5 minutes of looking is in Industrial Computer Supplies catalog: Software selectable timer watchdog with TTL out, adjustable temperature alarm, and optically isolated RS485/RS422 for $245.00. Add a relay for $295.00. Evidently the board dates back to before everything had COM ports on the motherboard. Let's pass on the price - if I actually need one right away for a project I'm glad I can just order it from an established vendor, and Packard Bell doesn't want this in their system. There is probably a cheaper one somewhere if you hunt around. Order 100 from Frank. -- Peter Dufault Real-Time Machine Control and Simulation HD Associates, Inc. Voice: 508 433 6936 dufault@hda.com Fax: 508 433 5267