On Saturday, October 15, 2011 12:12:40 PM Bruce Klawiter did opine: > Trying to get rid of spikes, see image 8 here: > https://sites.google.com/site/bmklawt/home/pid-tuning > > See the jitter here: http://www.youtube.com/user/bmklawt > > >Probably not the root cause of the problem, but you might try > >commenting out all the backlash statements in your ini file. > > < > Tried this, no change > < > > >OK, well, this is looking like there is a problem in the servo amps. > >Maybe > > you need to check the + and - 15 Volts, or whatever the servo amps use > > >as the supply for their op-amps. Capacitors may have > > deteriorated and there is >noise on these supplies.. > > I checked this it has +15 volts and -15.2 volts, I don't know how to > check for noise < > > >Possibly you have grounded a circuit that should not be grounded to the > >>machine's common ground. > > Grounding > problem has been mentioned a lot, I always assumed ground was ground, > everything in the control is grounded to the chassis. It is pretty much > as it was originally. I have a crude schematic here, maybe someone can > find the problem: > https://sites.google.com/site/bmklawt/home/control-schematic > > >Another > > thought is that the logic signal that enables the servo amps is not > being >held at the right voltage, so the servo amps are right on the > edge of >enabling/disabling. This can cause a transient every time > the amp enables that >causes it to jump.. > > How would I check this? > > >polarity of the signals is important. The command input "SIG" is on J1 > >Pin 2. The > > signal common, for tach, command and anything else is J1 Pin 4. J1 Pin > 4 >needs to be connected to the ground of the DAC board. > > Well I am sure this is right if it is backwards the servos run away > > >If the connections are right, then I'd suggest running a big ground > >wire from the >servo amp chassis to the PPMC. > > Did this, no change > > >On the power supply that feeds the amps, is its output common grounded > >to something? And does the motor return line come back directly to the > >power supply common, without connecting to anything else along the way? > > Well there is two power supplies going to the amps so I am > confused, please see the schematic here > https://sites.google.com/site/bmklawt/home/control-schematic > I don't know were the motor return line is > I think you will have to find it. There has been a discussion of grounding here on this list just in the last 2 weeks or so, which your drawing isn't complete enough to tell if its right or wrong. Basically, everyplace your drawing shows as going to ground should go there on its own wire, and they should meet at one common bolt. There shouldn't be a measurable path to this bolt from any wire that has been disconnected from this bolt, it is the center of the 'star'. Any other ground will make a 'ground loop' and the circulating currents will develop voltages that can mess with the servo's. This could even call for remounting power supplies so they are isolated from the mounting if they are internally grounded.
> Your help is greatly appreciate > ------------------------------------------------------------------------ > ------ 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 > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Pilfering Treasury property is paticularly dangerous: big thieves are ruthless in punishing little thieves. -- Diogenes ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
