Re: My device stops receiving when powered from battery
Kees Zagers <[email protected]> Thu, 27 Sep 2018 14:37:07 +0200
| Newsgroups | gmane.comp.hardware.bus.can |
|---|---|
| Organization | SI-Kwadraat B.V. |
| Message-ID | <[email protected]> |
This is a multi-part message in MIME format. --------------6586B2DCC2C420E3897D7042 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit I guess it is the mixture of 5V and 3.3V transceivers. The SN65HVD230 is a 3.3 Volt device and the NXP TJ1051 a 5 Volt device. Your local supply will probably 3.3Volt, however the external battery will probably be a higher voltage. I guess the SN65HVD230 does not like that :-(. If your battery is below 4.5 Volt your NXP TJ1051's will not work :-( Kees Op 27-9-2018 om 13:51 schreef FLJ: > Regarding the battery, it can definitely supply enough power to all 4 > CAN nodes (this includes my device), because the working system is > built to drive an electric motor as well. The battery could power the > 4 nodes for hours if not days, since we are not powering the motor > until the issue with the CAN is figured out. We are not adding any > additional consumers. > > My device is a CAN logger, there is wiring in the system (CAN > connector) for this purpose. We are provided only with CAN-H and > CAN-L. For my understanding a common ground is ensured, since all > nodes are powered by the same battery. > > > > > On Thu, Sep 27, 2018 at 1:35 PM Christiano SA <[email protected] > <mailto:[email protected]>> wrote: > > At some point the battery would fail. > It would not be normal to plug infinite nodes into the system > without causing a side effect. Every battery has a max current. > > The external power worked because CAN Bus signal is differential > (A-B) as well as RS-485 is also. > I already saw in a book (Jan Axelson) saying that on RS-485 the > common GND must be next to the signals. In OBD-II interface, I see > that the GND goes along too. > But I have already tested a RS-485 system without common GND and > it worked, I do not know exactly how, it must have some protection > mechanism that automatically balances the commons. > > > > Sent: Thursday, September 27, 2018 at 7:09 AM > > From: FLJ <[email protected] <mailto:[email protected]>> > > To: [email protected] <mailto:[email protected]> > > Subject: [CANLIST] My device stops receiving when powered from > battery > > > > Hello everyone, > > > > as a software developer I'm completely perplexed by my current > problem. I > > only have basic HW knowledge and I mostly follow HW diagrams > designed by > > others. Until now I guess I was lucky. > > > > I have an embedded device built upon an STM32 F4 evaluation > board and I'm > > using a SN65HVD230 CAN tranceiver from texas instruments with it. > > > > I have a battery powered system consisting of 3 CAN nodes using > NXP TJ1051 > > tranceivers, I don't have much detail about the MCUs used. > > > > The system all alone communicates over CAN correctly as expected. > > > > If I connect my device to the system's bus, while I power my > device from an > > external power supply, everything works fine. I receive all the CAN > > messages I want to from the systems nodes. > > My device is configured in silent mode, I don't want to send > anything. > > > > As soon as I power my device from the same battery as the > system, I stop > > receiving CAN messages. My device itself is working when powered > from the > > common battery, meaning I can connect with the debugger to it, set > > breakpoints, etc.; only the CAN stops working. > > > > I've read a lot about common-mode voltage in the past few hours, > and about > > splitted termination, but I can't understand what the problem is. I > > would've rather expected or understood if the device wasn't > working when > > powered externally, but everything on the same battery should've > worked. > > > > Can anyone help me out please? > > > -- > Archives and useful links: http://groups.yahoo.com/group/CANbus > Subscribe and unsubscribe at www.vector.com/canlist/ > <http://www.vector.com/canlist/> > Report any problems to <[email protected] > <mailto:[email protected]>> > -- Kees Zagers SI-KWADRAAT B.V. Van Kemenadelaan 13 5674 PP NUENEN Tel. +31(0)40-2839582 [email protected] --------------6586B2DCC2C420E3897D7042 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 7bit <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body text="#000000" bgcolor="#FFFFFF"> <p>I guess it is the mixture of 5V and 3.3V transceivers. The SN65HVD230 is a 3.3 Volt device and the NXP TJ1051 a 5 Volt device. Your local supply will probably 3.3Volt, however the external battery will probably be a higher voltage. I guess the SN65HVD230 does not like that :-(. If your battery is below 4.5 Volt your NXP TJ1051's will not work :-(<br> </p> <p>Kees<br> </p> <br> <div class="moz-cite-prefix">Op 27-9-2018 om 13:51 schreef FLJ:<br> </div> <blockquote type="cite" cite="mid:CAOsOv4=FYNVH-Bn9xq1oviLPY7bEWm41nrmvNivDvZwgVQTs0g@mail.gmail.com"> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <div dir="ltr">Regarding the battery, it can definitely supply enough power to all 4 CAN nodes (this includes my device), because the working system is built to drive an electric motor as well. The battery could power the 4 nodes for hours if not days, since we are not powering the motor until the issue with the CAN is figured out. We are not adding any additional consumers. <div><br> </div> <div>My device is a CAN logger, there is wiring in the system (CAN connector) for this purpose. We are provided only with CAN-H and CAN-L. For my understanding a common ground is ensured, since all nodes are powered by the same battery.</div> <div><br> <div><br> </div> <div><br> </div> </div> </div> <br> <div class="gmail_quote"> <div dir="ltr">On Thu, Sep 27, 2018 at 1:35 PM Christiano SA <<a href="mailto:[email protected]" moz-do-not-send="true">[email protected]</a>> wrote:<br> </div> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">At some point the battery would fail. <br> It would not be normal to plug infinite nodes into the system without causing a side effect. Every battery has a max current.<br> <br> The external power worked because CAN Bus signal is differential (A-B) as well as RS-485 is also.<br> I already saw in a book (Jan Axelson) saying that on RS-485 the common GND must be next to the signals. In OBD-II interface, I see that the GND goes along too.<br> But I have already tested a RS-485 system without common GND and it worked, I do not know exactly how, it must have some protection mechanism that automatically balances the commons. <br> <br> <br> > Sent: Thursday, September 27, 2018 at 7:09 AM<br> > From: FLJ <<a href="mailto:[email protected]" target="_blank" moz-do-not-send="true">[email protected]</a>><br> > To: <a href="mailto:[email protected]" target="_blank" moz-do-not-send="true">[email protected]</a><br> > Subject: [CANLIST] My device stops receiving when powered from battery<br> ><br> > Hello everyone,<br> > <br> > as a software developer I'm completely perplexed by my current problem. I<br> > only have basic HW knowledge and I mostly follow HW diagrams designed by<br> > others. Until now I guess I was lucky.<br> > <br> > I have an embedded device built upon an STM32 F4 evaluation board and I'm<br> > using a SN65HVD230 CAN tranceiver from texas instruments with it.<br> > <br> > I have a battery powered system consisting of 3 CAN nodes using NXP TJ1051<br> > tranceivers, I don't have much detail about the MCUs used.<br> > <br> > The system all alone communicates over CAN correctly as expected.<br> > <br> > If I connect my device to the system's bus, while I power my device from an<br> > external power supply, everything works fine. I receive all the CAN<br> > messages I want to from the systems nodes.<br> > My device is configured in silent mode, I don't want to send anything.<br> > <br> > As soon as I power my device from the same battery as the system, I stop<br> > receiving CAN messages. My device itself is working when powered from the<br> > common battery, meaning I can connect with the debugger to it, set<br> > breakpoints, etc.; only the CAN stops working.<br> > <br> > I've read a lot about common-mode voltage in the past few hours, and about<br> > splitted termination, but I can't understand what the problem is. I<br> > would've rather expected or understood if the device wasn't working when<br> > powered externally, but everything on the same battery should've worked.<br> > <br> > Can anyone help me out please?<br> > <br> --<br> Archives and useful links: <a href="http://groups.yahoo.com/group/CANbus" rel="noreferrer" target="_blank" moz-do-not-send="true">http://groups.yahoo.com/group/CANbus</a><br> Subscribe and unsubscribe at <a href="http://www.vector.com/canlist/" rel="noreferrer" target="_blank" moz-do-not-send="true">www.vector.com/canlist/</a><br> Report any problems to <<a href="mailto:[email protected]" target="_blank" moz-do-not-send="true">[email protected]</a>><br> </blockquote> </div> </blockquote> <br> <pre class="moz-signature" cols="72">-- Kees Zagers SI-KWADRAAT B.V. Van Kemenadelaan 13 5674 PP NUENEN Tel. +31(0)40-2839582 <a class="moz-txt-link-abbreviated" href="mailto:[email protected]">[email protected]</a></pre> </body> </html> --------------6586B2DCC2C420E3897D7042-- -- Archives and useful links: http://groups.yahoo.com/group/CANbus Subscribe and unsubscribe at www.vector.com/canlist/ Report any problems to <[email protected]>