Colin, This sounds very strange, a 5 meter cable is not that long and should not be causing any problems.
You say that you have tried a different PI and LinkUSB but have you tried a different power supply? Also do you have a different type of 1-Wire master besides the LinkUSB that you could try? Eric On Jan 31, 2014, at 11:02 AM, Colin Tinker <[email protected]> wrote: > Paul > > I do have that thanks anyway. I know that open stubs can create > problems but I used it to see if it was the sensor I connected to it or > the cable or whatever it might be. If I connect a temperature sensor > on a 1 meter RJ45 cable it is fine and works as expected. If I use a > cable say 5 meters long with the same sensor connected it is not seen, > the light on the LinkUSB stays on all the time dimly and glows brigher > when my script checks the bus for the sensors temperature. I have had > this issue since the lightning strike 3 weeks ago. I am now using a > different Raspberry pi, a different LinkUSB or an RPI2 bought new after > the strike and new cables. As I say I have tested all the sensors and > they work fine all connected in series on 1 meter RJ45 cables. Use a > longer new cable to connect another sensor and every sensor on the > network disappears. > > I am at a loss I have tested all sensors and I have a cable tester which > shows all cables are straight through with no shorts or open circuits. > They all work fine for gig Ethernet. I have put my scope on the data > and return wires at the LinkUSB end and that does not show any noise on > the network even with a long cable connected to a sensor, only the calls > for the sensor are seen on it. > > I have built a new sensor to run parasitic and it works on a short cable > but not a long one. I have installed owfs on my Linux desktop and it > does the same. > > Any ideas welcome. > > Colin > >> >> ------------------------------ >> >> Message: 2 >> Date: Wed, 29 Jan 2014 08:32:35 -0500 >> From: Ziggy <[email protected]> >> Subject: Re: [Owfs-developers] 1-wire network problems >> To: "OWFS (One-wire file system) discussion and help" >> <[email protected]> >> Message-ID: <[email protected]> >> Content-Type: text/plain; charset=us-ascii >> >> Please check out Dallas/Maxim app note 148. Gives a lot of insight into >> making things work and why they don't. >> >> <http://pdfserv.maximintegrated.com/en/an/AN148.pdf> >> >> Open stubs are a bad thing and cause reflections on the wire, disrupting >> communication. They can also act like antennas, picking up noise which could >> be the activity you see on the LED - but not sure what drives it since I >> couldn't find a schematic for the LinkUSB. >> >> Paul >> >> On Jan 28, 2014, at 3:52 AM, Colin Tinker <[email protected]> wrote: >> >> Eric >> >> They are truly in series. The LinkUSB light will come on dimly all the >> time with a long cable with nothing attached to it and stay on all the >> time dimly. The light should only be on when there is traffic on the >> network. >> >> Colin >> >> >> Colin, >> >> Are your devices truly connected in series or are there some stubs? >> >> If you have a power injector in the system I?m not sure why the LinkUSB >> light would dim at all. >> >> Eric >> >> >> >> ------------------------------------------------------------------------------ >> WatchGuard Dimension instantly turns raw network data into actionable >> security intelligence. It gives you real-time visual feedback on key >> security issues and trends. Skip the complicated setup - simply import >> a virtual appliance and go from zero to informed in seconds. >> http://pubads.g.doubleclick.net/gampad/clk?id=123612991&iu=/4140/ostg.clktrk >> _______________________________________________ >> Owfs-developers mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/owfs-developers >> >> >> >> >> > > > ------------------------------------------------------------------------------ > WatchGuard Dimension instantly turns raw network data into actionable > security intelligence. It gives you real-time visual feedback on key > security issues and trends. Skip the complicated setup - simply import > a virtual appliance and go from zero to informed in seconds. > http://pubads.g.doubleclick.net/gampad/clk?id=123612991&iu=/4140/ostg.clktrk > _______________________________________________ > Owfs-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------------------------------ WatchGuard Dimension instantly turns raw network data into actionable security intelligence. It gives you real-time visual feedback on key security issues and trends. Skip the complicated setup - simply import a virtual appliance and go from zero to informed in seconds. http://pubads.g.doubleclick.net/gampad/clk?id=123612991&iu=/4140/ostg.clktrk _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
