Bruce Klawiter wrote: > Trying to get rid of spikes, see image 8 here: > https://sites.google.com/site/bmklawt/home/pid-tuning > > 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 > < > You may be able to use the AC range on a DVM, and check while the machine is moving, that might have an effect. The AC range of the meter should show just about zero, anything over 0.1 V AC is highly suspicious that there is ripple on the supply due to failed capacitors.
You also should do the same test on the motor DC supply, and definitely do this while the machine is moving. Anything over a volt or two on the AC range may be a problem, but this would not be as sensitive as the +/- 15V supply for the servo amp. >> 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 > No, this really doesn't have enough detail to tell what is connected. >> 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 > No, if you reverse the wires and ALSO reverse the sign of OUTPUT_SCALE it will go the right way. But, you probably have it wired right, anyway. >> 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 > One is the +/- 15 V supply, on J3, and the motors supply on J4. The return of the motor supply is to the minus of the big capacitor next to the servo amps on the drawing. But, if that was left the way Anilam did it, it is probably right. 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
