On 03/01/2017 06:42 AM, Roland Jollivet wrote: > I had always assumed that machine MPG's generated one state change per > click, but following Gene's discussion, I pulled out my 1988 Fanuc MPG, and > saw that it was also 4-states per click. Obviously, one 'pulse'/detent > > Does anyone know the rationale behind this? > I assumed one always wants one step per click, so why not use a 25ppr > encoder and use every change? > Used as currently is, it would have to be a software /4 to be useful. You > could also do a /2 or /1, but no-one ever wants a x2 or x4 on their MPG > It's always x10, x100 or whatever, so the count/detent would always have to > be n/4 x 1 .. or.. n/4 x10 in software. > > Alternatively, if I was going to make my own MPG, surely I would just make > a 25ppr encoder and make it 1 detent/change? > It's far easier for me to make, so surely it would have been for Fanuc too? > > What am I missing? > > Possibly that a 25 count dial would make the machine buzz horribly when jogging. I found that I had to insert a lowpass filter (THANKS, Jeff Epler) to remove this, even with a 100 count dial. I guess if you are going to put in a filter, then the 25 count dial would be fine. Maybe Fanuc didn't want to dedicate the CPU resources to the jog filter.
Jon ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
