On 10/29/2015 02:41 PM, Stuart Stevenson wrote: > Ok, > > new information > > new ram installed > new ppmc boards > no change in machine motion on the Y axis - the other axes run fine (they > might have been fine before and it may have been my misunderstanding). > once y motion has been started the axis moves until - A. estop B. motion > change by pressing the opposite motion button C. sometimes the axis will > stop on the motion direction change but most of the time it will just > change direction and continue the motion in the opposite direction. > > OK, this is different, and I really suggest checking the Y axis with Halscope, looking at : ppmc.0.encoder.01.velocity (hmmm, maybe on your older LinuxCNC version, there will only be delta) pid.1.error
And see what it is doing when it runs away. I'm guessing that it is either the encoder channel is doing something odd, like not reporting movement, or the DAC is getting left with a non-zero velocity when the jog command ends. If anything strange is found, run the ppmc diags program in the commtest mode. Also run the dactest mode (If you have a very old version of the diags it won't have this, I can send a newer version) this tests reliability of communication to the DAC board. Possibly the parallel port or the IEEE-1284 cable may have a problem. If the encoder and encoder board are working correctly, and the MIN_FERROR is set to something reasonable, then a servo divergence like this should be impossible. Boy, this is sure a weird one, wish I was there to have a look! Jon ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
