[rtl] Matrox Meteor2 drivers...
Hello RTL world. This question is slightly off topic but I'm wondering if anyone may know of an existing driver for the Matrox Meteor2 framegrabber under Linux? Any help would be appreciated. Thank you! - Tony Tony Mouawad, Software EngineerAg-Tronic Control Systems Inc.tel: (519) 322-2510fax:(519) 322-1036www.ag-tronic.com
[rtl] Recommended reading???
Can anyone recommend a few good books that deal with "real time" programming and operating systems at a very fundamental level. It seems I was only after a system that could do something EXACTLY everytime I needed it to do something and that's where rtlinux came into play. Now I'm even more curious about the evolution of real time OS's and the philosophies and the technologies... hmmm, I'm quite curious! - Tony
Re: [rtl] RTAI and RTLinux
I'm new to the RT world, but I'm curious... what significant challenges are there when working with dynamic memory and real time? Just the term "dynamic" gives us an indication that the mechanism would be undeterministic... but what's worse case here? Why is it impossible to have a "real time" dynamic memory manager? At worst, nothing is "real time", it's a matter of perception. If I lived in a world where my timing resolution is 1 sec at a time, then having a "dynamic" system ranging between 0 and 0.99s would be perceived as "real time", keeping in mind that we ignore any other "timing" details involved... maybe I don't quite understand the discussion but bottom line, what are the challenges involved here??? - Tony -Original Message- From: Paolo Mantegazza <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] <[EMAIL PROTECTED]>; [EMAIL PROTECTED] <[EMAIL PROTECTED]> Date: Thursday, September 07, 2000 2:52 PM Subject: Re: [rtl] RTAI and RTLinux >[EMAIL PROTECTED] wrote: >> >> On Thu, Sep 07, 2000 at 06:58:48AM +0200, Paolo Mantegazza wrote: >> > [EMAIL PROTECTED] wrote: >> > - . do we want to bet how long will it take to see a real time >> > memory manager in RTL? >> >> There is no such thing as a dynamic real time memory manager. > >In fact I was just betting there will be one in the future :-). > >> It's been some years since RTL has been available and we have >> many times had this silly discussion. >> >> The code for a simple version is trivial. >> >> >> Step 1: write some module code: >> In Linux init: >>ask for a soft RTL interrupt >>install a handler >> >> handler: >> read from request queue (could be a fifo) >> v = kmalloc( requested.space) >> *requested.result = v; >> pthread_wakeup_np(requested.thread); >> >> Step 2: write some RTL thread code. >> >> In rtl periodic thread; >> >>queue request. >>pthread_kill(pthread_linux(),kmalloc_irq); >>while( !request.result) >> pthread_wait_np(); >> >> Step3 : receive Nobel Prize. > >Since you like joking, I feel invited to go on ;-). > >Once more RTAI has no problem in doing that. RTAI fifos were already >based on the use of its srqs when RTL was still patching the kernel to >protect Linux tasks queues to be used with fifos in real time. > >In fact we (I, Steve and Pierre) discussed a similar solution before >they implemented theirs ideas, but they denied its usefulness because >was too much not deterministic, and they needed a truly fast minimal >latency dynamic memory manager for their applications. >So I was just pleased to have them add, and copyright, what I think is >an usefull service for RTAI. Recall that I support the idea that a reach >toolbox of mechanisms enhances user politics implementation freedom. > >Note also that RTAI calls what you name soft interrupts as system >requests and they are structured with two handlers, one for user and one >for kernel space. So it could be simple for a supervisory user space >process, acting as a user interface, to pre allocate memory in kernel >space for a new stack of a to be launched rt_task, or a larger one onto >which save an already in use stack, so that a real time task could be >dynamically resumed on a larger stack if needed, and many other fancy >things. However all those things were believed not satisfactory, because >tightened to Linux, and thus miles away from a minimal latency memory >management. > >Nonetheless RTAI exploits the idea of using an srq in relation to memory >managment, but just for kfreeing kmalloced memory when tasks are >deleted. > >Clearly I applied to have a Nobel Prize. They already promised me one >when the euro will be worth .001 dollars, and it seems it will happen >quite soon. > >Ciao, Paolo. >-- [rtl] --- >To unsubscribe: >echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR >echo "unsubscribe rtl " | mail [EMAIL PROTECTED] >--- >For more information on Real-Time Linux see: >http://www.rtlinux.org/rtlinux/ > -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
Re: [rtl] Press Controll
Hi Andrew, just ouf of curiosity... why not use a PLC? Is it because of the encoder interface? I've built several applications similar to yours and most were doable with a PLC system. When needed, I patched in a PC based user interface via serial comm to the PLC for monitoring or data handling. I only persue PC based real time systems when the application requires something that outperforms a PLC or when something that is extremely complicated to code. I guess price can be an issue... you get more bang for the buck out of a PC than a PLC. Until you take into consideration the harsh environment your system will work in... lots of factors to consider sometimes. Also, you dont have to worry about hard drive failure with a PLC. ; -) Just a thought... - Tony - Original Message - From: Andrew Hooper <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, August 23, 2000 6:12 PM Subject: [rtl] Press Controll > Hi, > > We have a press that we would like to controll using rti, or something > similar > i currently have the bones of a system setup using RTAI and mbuff, but since > its been close to a years since i set this up im wondering if there have > been > any advancments as to an interface and inviroment that would allow me to > set this up a little easier. > > What we have is the following. > > 40ton press with mechanical feeder, with an slodstate relay on the > controller, > hold the relay closed and the press will cycle, release and it will stop. > > Encoder that sits on the metal being feed and checks that the correct amount > is being feed. > > Magnetic Switch at TDC. > > What we are trying to acheive. > > Enter the Lenght/encoder count, Enter the QTY of peices wanted press enter > and the press will cycle until done. > > Each cycle the encoder is checked to see that the matereal has been feed > and the magnetic sensor is checkd to ensure that the press has reached TDC > before triggering another cycle. > > When each cycle is triggered incrament the counter by one. > > Simple Eh. :) > > Well i wrote the routine about one year ago, took the system and the info to > the > be installed and it has sat there for that year waiting for the electritian > to install > the interface, now its installed they have lost the paperwork on how it was > done > and somehow the HDD on the system has died (Guess What) No Backup :( > I could and should kick myself for that one > > Anyway, looks like im back at square one again. > > Any one have any ideas..? > > Regards > Andrew > > > -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
[rtl] usleep in RT
Does RT support usleep( ) from within a module? - Tony
[rtl] Programming UDP in RT
Just wondering if anyone has an examples for programming UDP sockets in RT module?? - Tony
[rtl] Programming sockets in RTL?
Is it possible to integrate a TCP/IP based server in an RTL module? I'm not sure how to do this using the RTL libraries. -Tony -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
Re: [rtl] NT and realtime
Daniel, from my experiences with NT no, it seems it is not capable of hard realtime. The OS is so undeterministic, interrupt latencies (depending on app) vary from anywhere between 100us to 1ms. I had a problem trying to handle a 1ms hard timed resolution process under NT. While testing, I found that NT only maintained about 75% stability with the process from time to time it liked to wonder off a few milliseconds doing who knows what!! However, I know you can purchase RT extentions for NT ($). So far, I am having remarkable success with RTLinux... and the stability of RTL is immaculate for what I am doing with it. - Tony daniel sheltraw wrote: > Hello Realtimers > > Dare I speak the words. But is Windows NT capable of hard realtime > scheduling? > > Daniel S. > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > -- [rtl] --- > To unsubscribe: > echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR > echo "unsubscribe rtl " | mail [EMAIL PROTECTED] > --- > For more information on Real-Time Linux see: > http://www.rtlinux.org/rtlinux/ -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl " | mail [EMAIL PROTECTED] --- For more information on Real-Time Linux see: http://www.rtlinux.org/rtlinux/
