On Friday 30 November 2007, Alan Condit wrote: >Chris Radek <[EMAIL PROTECTED]> writes: >> Yes just set the homing velocities to zero. That makes the axis >> reset without any search for switch or index. >> Also if using AXIS be sure to set [DISPLAY]LATHE=1 so you get the >> diameter readout etc. > >Chris thanks, that solves that problem. Now if someone can just answer my >encoder question. > >Alan > I'm not what you would call an expert, but as a CET & an emc user, I see no reason why any once per revolution pulse couldn't be used as a valid index pulse. The only provision would be one of the mechanical timing such that there is no chance, when turning either direction, of its pulse miss-matching the encoder counter. One could also divide the encoder by (you said 256) by running it through a 4 bit counter and using the overflow for the index. For that to work, one should have a positive spindle stop, rotate it against the stop, and tap a button to zero the 4 bitter. It should stay in step then as long as power is applied. This, once the encoders output is a quadrature pair of signals, is a one chip solution in most cases.
Being me, I think I'd try that before doing mechanical things. My favorite programming language is solder anyway. Borrowed from Steve Ciarcia, Circuit Cellar magazine. -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Quantity is no substitute for quality, but its the only one we've got. ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
