On Fri, 2007-07-20 at 11:13 -0500, Jon Elson wrote: > Kirk Wallace wrote: > > My lathe has a pulse generator with an index signal, but while trying to > > hook it up to my UnivPWM controller, I am beginning to think that it's > > not compatible with the controller. Are the encoder inputs only > > compatible with quadrature encoders? I can utilize a software encoder > > counter in HAL on another parallel port, but I believe that software > > counters would be too slow. Is fitting a quadrature encoder my only > > option? > > The UPC has quadrature inputs, and the EMC2 driver and threading > code all requires encoder counts, and a reset to zero on the > index pulse.
This clears up allot. I hooked up the position signal to B and the index signal to Z. I got 0 1 0 1 0... on count with halmeter but no indication from halmeter on the index or index-enable. Is the index update also dependent on the quadrature signal? > So, your "pulse generator" just has one channel of > pulses? Yes > I can see one way to make this work, which is to delay > the single pulse with an RC delay or a one-shot circuit to turn > it into a simulated quadrature signal. > > First, here's what I'd do, is connect the pulse output to the > UPC's A encoder input, and connect a 10 K Ohm resistor between > the A and B encoder inputs. Then, connect a .01 uF capacitor > from the B input to ground. This will create a 100 us delay > between A and B, which should satisfy the counter as a valid > quadrature pattern. Very clever. I'll have to play with this. Though, just for fun, I'll take a stab at the numbers. Let's say I want to run the spindle at 3k rev./min. with a 2k pulses/rev. encoder. This gives 6m pulses/min. or 100 kHz or 10 us? If that is right, then I would have encoder problems at higher speeds? > Try this first, if it doesn't work, I can give you instructions > to make a delay with a one-shot chip. > > Jon I bought an extra encoder disk and sensor from U. S. Digital, so I will probably replace the pulse generator with a new encoder. Thanks Jon. Kirk Wallace ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
