On 03/01/2017 04:42 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 don't know, but in my opinion ... there are four pulses per quadrature cycle and the pulses have to follow a proper sequence for forward and reverse rotation. This can produce a more reliable input for each detent location because a proper set of pulses are needed. If there is any electrical or mechanical noise (detent close to a pulse, machine vibration) and we use only valid cycles, rather than raw pulses, we will have a more robust input. It is sort of like using parity checking on data words and maybe hysteresis (more than one pulse to change a state either way). -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/ ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
