From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Hartkopp Subject: Re: read() question from newbie Date: Tue, 17 Apr 2012 08:08:18 +0200 Message-ID: <4F8D08D2.3090701@hartkopp.net> References: <4F51DEF0.9060501@hartkopp.net> <4F553BDA.8060106@hartkopp.net> <4F553CA5.8080704@hartkopp.net> <4F56701E.3020104@hartkopp.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mo-p00-ob.rzone.de ([81.169.146.161]:50490 "EHLO mo-p00-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754307Ab2DQGIT (ORCPT ); Tue, 17 Apr 2012 02:08:19 -0400 In-Reply-To: Sender: linux-can-owner@vger.kernel.org List-ID: To: Michael Economides Cc: linux-can@vger.kernel.org On 17.04.2012 06:16, Michael Economides wrote: >> >> I assume there is a CAN bus problem: >> >> - wiring (CAN_L/CAN_H) >> - correct CAN termination (2x 120 Ohms) >> - different bitrate >> > > I think you are right, but I have checked that, it looks ok. I will > check again. > > I am using a PCAN USB adapter, and the PCAN software says there is an > "acknowledge error" when it sends a frame to my Linux board. This is an indication for a missing counterpart CAN node: - Wrong connection wiring - Wrong termination - Wrong bitrate > > When the Linux board tries to send a frame to PCAN, the PCAN software > says "form error acknowledge delimiter". > > It seems this is the same error in both cases, just worded differently. Yes. But this means the same regarding the obvious problems. > > In your opinion, is this most likely a hardware issue? Or is there > still some way I could be doing something wrong at the software level? Did you swap CAN_H / CAN_L ?? It's definitely one of the three points above. No SW problem ... Try to add a third CAN node - if you have one. Regards, Oliver