Greetings Peter C.W. One of the things I notice while monitoring for decent quadrature even at low rpms, is an apparent cyclic variation that is several times per revolution. It is a 60 tooth gear, and the servo thread is the usual near 1 kilohertz. There is also a 200hz thread which handles to manual jog encoder wheels, but the main servo thread is the read-process-write system.
Now, up to about 300 rpms, there does not appear to be any missing encoder outputs to the A nd B inputs, but above 300 revs it starts to skip a pulse occasionally, and the tach needle gets nervous jittering low at the same time. Then it occurs to me that the time between samples is causing the narrower pulses to be missed at almost random counts because they are going by at just about servo-period time so I'm seeing 15 to 20 pulses then missing 4 or 5 when it should be at 600 revs, but is jittery and showing 570 or so. Which tells me the encoder's velocity output, is not keeping up with it either. It appears to me that, unlike on the 5i25, there does not exist a sample time-frequency facility, or is it there but un-setp'd because I have zero docs of this other that what it spits out at initialization time. hm2_7i90.0.encoder.sample-frequency is being reported as 25000000, which seems like it s/b fast enough, but whats its actual range? What else in useing it correctly, do I not know? Whats the cure IOW? Thanks Peter, and stay safe now. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
