Ed wrote: >Sooooo... could it be that Dell system board parallel ports >have a very small error rate when hammered by EMC? > Anything is possible, and I use them in a different way. But, I use Dell Optiplex (commercial-grade) desktop systems as much as possible. I use the parallel ports in EPP mode as a communication channel to my line of stepper and servo controllers. So, in a typical system, the CPU reads 12 bytes of position information and sends 6 or 12 bytes of velocity info 1000 times a second, all the time EMC is running. I also have some test programs that write out and read back the same registers about 5000 times a second, and compares the data for errors. I typically run this for 100,000 test cycles, but have run it for hours without error.
Now, the other difference is I'm not driving opto-coupled stepper drivers directly from the parallel port, and I don't have the dependence on step-direction timing that some stepper drivers are known to have. Jon ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
