It does sound similar. Yaskawa does have a type of absolute encoder with a battery backup. Based on the datasheet their absolute encoders have connector pins for a battery but these ones do not. These do have hall signals to allow initial commutation. I assume that the yaskawa drives commutate on the hall signals until the reference point is crossed and then adjust for normal operation.
If you had to drive fanuc encoder/servos from a bldc component how would you (roughly speaking) configure them? -Curt On Sun, May 10, 2020, 10:50 PM Jon Elson <el...@pico-systems.com> wrote: > On 05/10/2020 07:20 PM, Curtis Dutton wrote: > > I have been able to get the yaskawa sigma5 motors turning with the bldc > > component in qh mode. > > > > The encoders are a sort of hybrid incremental/absolute encoder. Once they > > pass the index point a flag and an offset are returned in the encoder > data > > that allows the exact rotor angle position to be computed. > > > > I'm trying to find the best path forward for facilitating commutation. > Any > > guidance would be appreciated. > > > Fanuc has two types of serial encoders. ABS and INC, for > absolute and incremental. > The incremental type only provide correct shaft angle when > battery backup is provided. > If the battery is disconnected or drained, then you have to > manually crank the motor over > one full turn so the encoder can see the index position. > Then, the controller can determine > commutation from the encoder data. > > The absolute type have an additional low-res track that > provides a 1024 count per quadrant > data that is aligned to the motor poles, so a drive could > immediately get commutation data > when encoder power is on. Although Fanuc provides a backup > battery for these encoders, > it seems it is not totally necessary. > > Perhaps the Yaskawa also have provision for battery backup? > The flag changing when index is sensed > sounds just like what the Fanuc encoders do. > > Jon > > > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
