From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45F31F3C.6090009@domain.hid> Date: Sat, 10 Mar 2007 22:12:28 +0100 From: Wolfgang Grandegger MIME-Version: 1.0 Subject: Re: [Xenomai-help] RTCAN and tsc References: <200703091538.54236.paul_c@domain.hid> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Daniel Schnell Cc: xenomai@xenomai.org, Bernard Dautrevaux Daniel Schnell wrote: > roland Tollenaar wrote: >> What baffles me a bit then is that the behavior cannot be classified >> as very "Real-Time" can it? > > Real-Time does mean the system reacts in time. There is nothing a > software can do if the hardware is not meeting your requirements of > beeing in time. Having reliable 0.5 ms real-time is e.g. for us > absolutely real-time and we chose carefully our hardware components that > this will never be exceeded. For us Xenomai and RTCAN on a MPC5200B > platform do a good job. > > I cannot imagine that the developers of >> rt-can overlooked this. I doubt that it will be possible to run a >> discrete state-space controller successfully on a platform that >> juggles around its period-times as badly as I am experiencing. And I >> still need to read discrete IO and write DIO and AIO to another CAN >> node which is not yet even connected. > > Choose your hardware carefully. Parallel port CANS are certainly much > slower than e.g. PCI adapters. On a Laptop you have the possibility to > add e.g. PCCARD CAN. But before purchasing I would check how these are > supported and which typical access times you can expect. USB CAN is > certainly even slower, so this will be no option. To confirm that, the PCAN dongle is a nice cheap device for low CAN speeds but not appropriate for 1MB/s. Please ask PEAK for more detailed information (e.g. linux@domain.hid). Wolfgang.