On 01/26/2014 11:54 AM, Charles Steinkuehler wrote: > I'm working on adding software encoder support to the BeagleBone PRU > code. Counting up/down is easy, but I'm wondering how to deal with the > index pulses. Both the Mesa VHDL code and the existing software encoder > component have quite a variety of options, and I'm wondering if it is > necessary to support them all (more options = longer code = lower > operating frequency). > > If you use encoders on your machine, what options do you have set for > the HAL component, and (if you know) what is the maximum pulse frequency > for your machine? > > Well, I only use hardware encoders, and the minimill has 4:1 belt reduction, 16 TPI screws and 500 cycle/rev encoders, so that is 128000 counts/inch. At 60 IPM, that is 128,000 counts/second. That is a pretty extreme case.
The problem with the index is it is noise sensitive, and unless you put a totally arbitrary delay on it, you can't do much to filter out noise on that channel. (I don't know if you are going to have any filtering on the quadrature, either.) Jon ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
