John Kasunich wrote: > Stuart Stevenson wrote: > >>Gentlemen, >> I hooked the scope to ppmc.0.encoder.02.index-enable and >>ppmc.0.encoder.02.position. The position trace showed rising as it >>traveled from left to right and at the index-enable pulse the position >>trace showed falling as it traveled from left to right until it >>reached zero. I could vary the angle of the falling slope of the >>position trace by changing the rapid travel speed of the axis. The >>position trace did not fall to zero at the falling edge of the >>index-enable pulse. >>Thanks >>Stuart > > > That is a conclusive result - there is a problem with the hardware, > such that it is reporting "I got an index pulse" but not resetting > the count. Hopefully Jon can fix that in the FPGA. I have made a change to the FPGA configuration, but I still have VERY big doubts that this has anything to do with it. I tested my change, and it works just like it did before the change. (For a moment, I thought something had changed, but I had managed to knock a wire loose on the Y encoder and the index pulse wasn't going through at all. And, it kept searching, just as one would expect.)
Anyway, it ocurred to me that the exact order of real-time modules activated in the thread may be very important for homing to work. I found some other latch-type functions needed a very specific order to work. That was the spindle sync for threading, which is a somewhat similar latching action. Here's the list from my ppmc_load.hal : # set up the realtime thread # read inputs first addf ppmc.0.read servo-thread # then run the motion controller addf motion-command-handler servo-thread addf and2.0 servo-thread addf estop-latch.0 servo-thread addf motion-controller servo-thread # then the PID loops addf pid.0.do-pid-calcs servo-thread addf pid.1.do-pid-calcs servo-thread addf pid.2.do-pid-calcs servo-thread addf pid.3.do-pid-calcs servo-thread # write outputs last addf ppmc.0.write servo-thread I will bet if the sequence of ppmc read, then motion-controller, then ppmc write isn't maintained, it could affect homing. 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
