another bizarre architecture
in [Embedded]
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From: John Doty on 8 Feb 2007 13:20 rickman wrote: > If C had an easy way to interactively test routines as they were > written, I would say C was the clear winner (no stack to fuss with). http://www.newtonlabs.com/ic/ Not an endorsement, I've never used this. -- John Doty, Noqsi Aerospace, Ltd. -- Specialization is for robots.
From: CBFalconer on 8 Feb 2007 15:20 Jerry Avins wrote: > Jonathan Kirwan wrote: > > ... > >> Hmm. Never mind about Lua. It's not c. Just c-like. But there >> do seem to be other c interpreters out there that are c and not >> c-like, given some of the google results I've just skimmed. > > Whatever happened to InstantC? I have a copy for DOS available to > anyone who wants it. Just ask. There is also something called ch. Seemed quite useful when I tried it a few years ago. -- <http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.txt> <http://www.securityfocus.com/columnists/423> "A man who is right every time is not likely to do very much." -- Francis Crick, co-discover of DNA "There is nothing more amazing than stupidity in action." -- Thomas Matthews
From: Rich Grise on 8 Feb 2007 17:31 On Thu, 08 Feb 2007 09:29:26 -0800, John Larkin wrote: .... > I don't like interrupts. The state of a system can become > unpredictable if important events can happen at any time. A > periodically run, uninterruptable state machine has no synchronization > problems. Interrupts to, say, put serial input into a buffer, and > *one* periodic interrupt that runs all your little state blocks, are > usually safe. Something like interrupting when a switch closes can get > nasty. So, when you're testing an engine, do you sample all of your inputs fast enough to keep it from blowing up if, say, some valve breaks or it loses a turbine blade? Or is that the kind of thing that even a vectored interrupt couldn't be fast enough to handle? And, just out of curiosity, have you ever actually blown up an engine? I've heard ULs about such things - or maybe one of your customers, prompting them to buy your controller? ;-) Thanks, Rich
From: John Larkin on 8 Feb 2007 18:34 On Thu, 08 Feb 2007 22:31:45 GMT, Rich Grise <rich(a)example.net> wrote: >On Thu, 08 Feb 2007 09:29:26 -0800, John Larkin wrote: >... >> I don't like interrupts. The state of a system can become >> unpredictable if important events can happen at any time. A >> periodically run, uninterruptable state machine has no synchronization >> problems. Interrupts to, say, put serial input into a buffer, and >> *one* periodic interrupt that runs all your little state blocks, are >> usually safe. Something like interrupting when a switch closes can get >> nasty. > >So, when you're testing an engine, do you sample all of your inputs >fast enough to keep it from blowing up if, say, some valve breaks or >it loses a turbine blade? Or is that the kind of thing that even a >vectored interrupt couldn't be fast enough to handle? Polling at, say, 1000 times a second is plenty fast enough to save an engine, if it can be saved. In the case of an overspeed, the actual rpm limit check would be done in software, so there's no overspeed interrupt as such. If you snap a shaft in the hp stage of a big steam turbine, the blades *will* fly off before you can close the steam valve. > >And, just out of curiosity, have you ever actually blown up an engine? No, but I almost ripped a ship off the dock at Avondale Shipyards, on the Mississippi. I got it up to almost 60 RPM while tweaking a nonlinear function generator (120 RPM is full power.) >I've heard ULs about such things - or maybe one of your customers, >prompting them to buy your controller? ;-) We are doing overspeed trip stuff these days. That's scairy. My customers do deliberately destroy a jet engine at full speed, to make sure the blade containment is adequate. The big commercial jet engines have a huge band of epoxy-kevlar wrapped around the front of the engine to catch the big (~~12 foot) fan blades. John
From: Jim Thompson on 8 Feb 2007 18:42
On Thu, 08 Feb 2007 15:34:45 -0800, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Thu, 08 Feb 2007 22:31:45 GMT, Rich Grise <rich(a)example.net> wrote: > >>On Thu, 08 Feb 2007 09:29:26 -0800, John Larkin wrote: >>... >>> I don't like interrupts. The state of a system can become >>> unpredictable if important events can happen at any time. A >>> periodically run, uninterruptable state machine has no synchronization >>> problems. Interrupts to, say, put serial input into a buffer, and >>> *one* periodic interrupt that runs all your little state blocks, are >>> usually safe. Something like interrupting when a switch closes can get >>> nasty. >> >>So, when you're testing an engine, do you sample all of your inputs >>fast enough to keep it from blowing up if, say, some valve breaks or >>it loses a turbine blade? Or is that the kind of thing that even a >>vectored interrupt couldn't be fast enough to handle? > >Polling at, say, 1000 times a second is plenty fast enough to save an >engine, if it can be saved. In the case of an overspeed, the actual >rpm limit check would be done in software, so there's no overspeed >interrupt as such. If you snap a shaft in the hp stage of a big steam >turbine, the blades *will* fly off before you can close the steam >valve. > >> >>And, just out of curiosity, have you ever actually blown up an engine? > >No, but I almost ripped a ship off the dock at Avondale Shipyards, on >the Mississippi. I got it up to almost 60 RPM while tweaking a >nonlinear function generator (120 RPM is full power.) > >>I've heard ULs about such things - or maybe one of your customers, >>prompting them to buy your controller? ;-) > >We are doing overspeed trip stuff these days. That's scairy. > >My customers do deliberately destroy a jet engine at full speed, to >make sure the blade containment is adequate. The big commercial jet >engines have a huge band of epoxy-kevlar wrapped around the front of >the engine to catch the big (~~12 foot) fan blades. > >John > I have spun communication satellites on a test stand at Honeywell Satellite Systems Division. I stood behind a huge building pillar in case it decided to do untoward things ;-) ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food. |