maybe another option should be added --device-reconnect-time=0 (don't use recoonect timeout) --device-reconnect-time=10 (reconnect after 10 seconds)
2012/1/27 Roberto Spadim <robe...@spadim.com.br>: > HIS PAUL READ THIS TOO, MAYBE A BETTER SOLUTION FOR BUS MASTER SPECIFIC > :D i found this too with ds2480b! > maybe a single workaround (ugly, but works) is a counter at device > for example after 10 reads, close and open device (/dev/ttyUSB0 or other > device) > this works like cron restart, but it's faster and don't need user to > configure a cron server (in ARM this must be compiled on some distros > or in android devices) > maybe a command line could help a lot (in another post i talked to > paul to add a force bus master type at command line, maybe this could > work too, but this one is another option) for example: > --device-reconnect-counter=0 (don't use reconnect) > --device-reconnect-counter=100 (after 100 complete(send/receive, or > send/timeout) commands reconnect) > this could be good for rfc2217 devices with a noise internet/ethernet > network too =D > i don't know if we should execute a bus master auto identification > after reconnection (check if we are using a ds2480 or a bit bang > serial por for example...) maybe the other command (force a bus > master) could help here > > 2012/1/27 ekgnkb3d <achi...@gmx.de>: >> >> Hi all, >> probably I've found a funny bug in the owserver in relation to USB >> Bus-Master and longer cables. This was mentioned before in >> http://old.nabble.com/Re%3A-How-to-enable-statistics--p33202282.html this >> posting very fuzzy, but now I was able to reproduce it in my lab: >> >> 1. Install OWFS 2.8p13 or p14 on an ARM9 400MHz >> 2. Connect one DS9490R USB Bus-Master >> 3. To provoke the error to appear fast, use an extra long cable of about >> 200m >> (28nF, e.g. SFTP, see simulation tool below) >> 4. Connect one DS18B20 to the cable, with Vcc powered to +5V >> 5. Start owserver with "-uall" >> 6. Start a client polling for the temp 2 times a second, eg owread or an >> owcapi application >> >> This works fine for about 2 to 20 minutes. If cable is shorter, 2.8p14 is >> used or other quirks are done (see remarks below) it can last for days and >> weeks. >> But suddenly it don't return the temp and don't show an error, even the >> device is not shown in owdir anymore >> >> One workaround: >> Restart the owserver, than it works again for 2 - 20 minutes until it >> suddenly don't return any temp. >> >> Another workaround by keeping the owserver-process alive: >> Truncate the cable to about 170m (25nF), than it works again for about 2 to >> 20 minutes. >> But suddenly it return an errno=22, the device disappears again in owdir. >> Truncate the cable again to 50m (8nF), this now works forever, I've checked >> at least for several month :-) >> >> Some remarks: >> - To simulate the long cables and the different length I made a >> capacity-cascade of 8 parallel >> capacities (0.1nF, 0.22nF, 0.47nF, 0.82nF, 1.5nF, 3.3nF, 6.8nF, 15nF and >> an 8-pol DIP switch >> between pins OWDATA and OWRETURN) this allows simulating cable length of >> 1m to 200m. >> - Beside the simulation, exactly the same behavior appears every week, at a >> real installation >> with a real cable of about 100m. >> - It have nothing to do with star- or other bad network topology, even >> a single cable with a single device at the end is enough to reproduce it >> - Disconnecting the cable and wait for minutes, or shorting the device don't >> solve the problem, >> only restarting the owserver or truncate the cable. >> - This is not dependent from dedicated pieces of hardware, it is >> reproducible with several DS9490R, >> several DS18B20, several ARMs and several types of cable. >> - In case several devices are connected to the bus, they all get the problem >> exactly at the same time, >> or came back when reducing the capacity/restart owserver together >> - I've tested also networks via I2C DS2482-100, this works fine since month, >> no problem here. >> I've not tested serial bus masters >> - It looks like the communication capabilities of the USB bus-master is >> reduced in stages: >> 0. After owserver restart it is able to drive 28nF at extreme. >> The statistics counter grow slowly, except the 3 search_errors which >> stay at 0 >> 1. Error stage: Now it can only drive up to 25nF, but the change is not >> smooth, it is an abrupt state >> change. This is stable for a while, no drifting, I've tested this with >> my cascade, reproducible for >> meanwhile dozens of tests: NOK >= 25.2nF, OK <= 25nF. >> Now the statistics counter stays at the last value, they don't grow >> further, even if the >> capacity is above 25nF. >> 2. Error stage: Now it can only drive 8nF, again no smooth transition, it >> is an abrupt state change. >> This seems to be stable forever, NOK >= 8.2nF, OK <= 8nF. >> Now the statistics counter stays, except the 3 search_errors they grow >> fast if the capacity >> is above 8nF. >> - The steps to reproduce, mentioned above, are aimed to see the error as >> fast as possible. There a >> several methods to delay the problem appearance, which is helpful when >> needing the OW-network, >> but none of them really solve it: >> - Use shorter cables from beginning onwards, start with 100m cable will >> cause the problem to >> appear after 3 to 14 days. Maybe below an dedicated length the problem >> completely disappear, >> but I need this length >> - Using 100 Ohm serial resistors after the bus-master, before the cable >> will shift the problem >> further by about 50% >> - Use parasitic power of the DS18B20 with Vcc to GND and remove the +5V >> from the cable. >> This will reduce the capacity and therefore allows longer cable or >> delays the error appearance. >> - Daily restart the owserver via cron-job :-( >> -- >> View this message in context: >> http://old.nabble.com/Problems-in-owserver-with-USB-and-longer-cables-tp33213551p33213551.html >> Sent from the OWFS - Dev mailing list archive at Nabble.com. >> >> >> ------------------------------------------------------------------------------ >> Try before you buy = See our experts in action! >> The most comprehensive online learning library for Microsoft developers >> is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, >> Metro Style Apps, more. Free future releases when you subscribe now! >> http://p.sf.net/sfu/learndevnow-dev2 >> _______________________________________________ >> Owfs-developers mailing list >> Owfs-developers@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/owfs-developers >> > > > > -- > Roberto Spadim > Spadim Technology / SPAEmpresarial -- Roberto Spadim Spadim Technology / SPAEmpresarial ------------------------------------------------------------------------------ Try before you buy = See our experts in action! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-dev2 _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
