Actually, the real design flaw was in the backup with an independent battery powered monitor that sounded an alarm that noone heard and was supposed to drop the curtains and allow fresh air to flow, but the ropes got tangled when dropping. Since it was independent (i.e. designed and installed by someone else), my real mistake (and lesson) was trusting that it worked. The experience of failure was really golden because the hosting company was given the opportunity to see what could happen if they didn't come up with a better curtain drop. My point was that since then, I don't sweat the failures and sometimes even entice them because they always pay dividends and tell me where to concentrate my efforts next time, and when given the chance to share my experience, I will - even though it means I have to admit to being less than perfect - because my failures can not only help me, but other people walking down the same path. All that said, there's no substitute for experience, and therefore only so much one can learn from hearing about mine. Thanks, Tony bob.axtell@gmail.com wrote: > Well- thought out, Olin. > > --Bob > > On 1/9/09, Olin Lathrop wrote: > >> Dr Skip wrote: >> >>> Always consider the remote possibilities (and losing comm isn't so >>> remote), and ask what-if, then when you've got it covered, ask what >>> if that fails... ;) >>> >> Exactly. The real design flaw was not that the system was susceptible to >> lightning, but that there was no backup or independent monitoring. >> >> Stuff fails. That will always happen. Better designed systems may fail >> less, but anything can fail. Given the cost of failure, both monetarily >> and >> morally, why the heck wasn't there at the very least some independent >> monitoring that would alarm if the temperature, pressure, or amonia >> concentration got past some level? This would be completely battery >> operated and send a RF message to various alarm stations, or call on a cell >> phone or something. What would have happened if the power went out? What >> about a redundant system controlling every other fan and louver? If one >> system failed, the other would try to compensate, and a alarm would go off >> in the mean time so that a human would show up and run things manually in >> the short term if needed. >> >> >> ******************************************************************** >> Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products >> (978) 742-9014. Gold level PIC consultants since 2000. >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> >> -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist