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 wonder why it shows up so consistently for you, and so rarely for Jon (and other users of his cards). Do you have very high resolution encoders? You might want to try a very slow HOME_LATCH_VELOCITY. If the movement is slow enough that you get less than one count per servo period, that will make the index pulse wider and less likely to be missed. I'm assuming you are using the default SERVO_PERIOD of 1000000 (one million nanoseconds, or one millisecond). If so, then try setting HOME_LATCH_VELOCITY to 500 / INPUT_SCALE. If your scale is 20,000 counts per inch, set the latch velocity to 500/20000 = 0.025 inches per second, and see if that makes a difference. That will make the latching phase of homing very slow, but normally the machine only moves a couple tenths of an inch in that phase. That isn't the ideal solution, but if it works, it will let you move on with your project before the hardware is fixed. Regards, John Kasunich ------------------------------------------------------------------------- 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
