Bruce Klawiter wrote: >>> Well I hope it is solved and I don't even know how I did it. >>> >> OHHHhhh NOOooooo! That's the worst kind, as it can come BACK! >> > I know, I spent the rest of the day trying to get the twitching to come > back so I would know what the problem was, but I can't. > > It is almost impossible to make a bad connector go flaky on demand. Any messing with it generally cleans the contact plating and makes it stay good for a while. >> Well, this is NOT OK! .1 V AC on the minus power supply to the op >> amps in the servo amp is a real problem. And, it isn't your meter, >> as the + side is reading .001, which is fine. >> > > Well then I will have to find a new power supply. > Or just replace the bulk filter cap for the minus side. it ought to be easy to locate these caps, they should be the biggest ones in the supply. > >> Yes, the DAC outputs have a signal pin and a ground pin. >> The encoder board also has a ground pin for each encoder. >> > With only the encoders plugged into the PPMC boards the D-sub > connector does not show ground. > Right, in many units the encoder is totally isolated from machine frame for best noise immunity. > OK let make sure I am saying this right with only the encoder > plugged in and my meter set to ohms, one lead on the D-sub > connector and on on the chassis it shows an open circuit. If I plug > in the amp to the DAC or the parallel cable my meter shows a dead short. > Not that this helps of changes anything I just want to make sure I > am explaining it rigth > > Would there be any benefit to moving all the grounds to one one point, this > would be fairly easy to do. > Since it is now working, I would be very afraid to change the ground arrangement, as it could cause a ground loop situation. If you are positive you can put it back if it causes a problem, then you can try it. But, Anilam may have spent considerable time putting the ground system the way it works best. You have no way to know about that.
Jon ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2d-oct _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
