On Monday 20 June 2005 04:38 pm, Jan Kandziora wrote: > Dear Paul, > > I've investigated further on the problem I described last week (in the > thread "owtcl and writing data"). > > It seems to be related to EMC: Nearly every time I switch on a large > 240/24V AC transformer I need for my project, I get a single error of the > kind I described. But sometimes, it is even a cascade of such errors, which > I can't bring into connection to any action I took (not). Maybe, it was the > fluorescent light on last week, but today, I didn't turn them on and still > got cascades of such errors (over about 1 minute). > > Then again, everything is fine for a couple of minutes. > Is it possible to add shielding? > I checked for USB errors with dmesg, and got very few USB disconnects > (about 1 of 30 times), but no other USB link layer errors. On the most > tries, only the 1-wire seemed to be affected. > The question is what is the program/port's state after one of these errors. It seems like there is nor recovery after an error. (i.e., the system doesn't work intermittently, only yes or no). If the error causes the USB port to close, life is easy.
We can re-open the USB port more easily than a full restart. We don't need to enumerate the devices, or resort the internal data structures. > I tested all this with the tcl script I posted before, and put an > > OW::finish > OW::init usb1 > > into the catch sequence to restart on error. Slow, but worked. > > > As there is little to do against EMC, I would suspect to change the > software a way it automatically reinitialize the connections if there is an > (until now) unrecoverable error. That leads me to following questions: > > 1. Is there any way to detect an "unrecoverable" error on bus side? > 2. I want to use owserver. You offered to change owserver to restart the > connection automatically: How is the development status for this? > 3. Is there any way to process the init sequence faster? For USB errors, it > would not be so dramatic if it takes 3 to 5 seconds to recover, as I expect > them to be very rare. However, the 1-Wire error happens *every time* a big > inductive load is switched near the device, so a faster recovery would be a > big help. > Ho do I tell the "1-wire error" from normal failures? (Wrong addresses, bits lost, ...) > Kind regards > > Jan > > > ------------------------------------------------------- > SF.Net email is sponsored by: Discover Easy Linux Migration Strategies > from IBM. Find simple to follow Roadmaps, straightforward articles, > informative Webcasts and more! Get everything you need to get up to > speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
