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General Mach Discussion / Re: Deckel Mach Retrofit
« on: August 15, 2007, 03:56:21 PM »
"" I am assuming that the control assumes the servo is "caught up" when the control ceases to output additonal pulses."""
Alan, I don't think the control "knows" much of anything about the servo loop except that it has or has not reported an error.
If the loop is doing it's job, it cannot continue if it hasn't positionally responded correctly to the step input, so the axis will "have" to be in position for that next set of streaming steps or the loop would have already faulted out. It can't just take the next series of steps and "forget" it didn't make position on the first stream.
If the servo is "catching up" by applying more power at the moment the change of direction comes, I have to presume (this is over my head), that the drive has a buffer and the servo will continue to catch up...or fail.
It will continue to attempt to make the first position, not just "give up" and start taking new steps.
I think it is fractions of a second we are talking about here. The drive will fault before that buffer is overfilled and steps lost.
Sean
Alan, I don't think the control "knows" much of anything about the servo loop except that it has or has not reported an error.
If the loop is doing it's job, it cannot continue if it hasn't positionally responded correctly to the step input, so the axis will "have" to be in position for that next set of streaming steps or the loop would have already faulted out. It can't just take the next series of steps and "forget" it didn't make position on the first stream.
If the servo is "catching up" by applying more power at the moment the change of direction comes, I have to presume (this is over my head), that the drive has a buffer and the servo will continue to catch up...or fail.
It will continue to attempt to make the first position, not just "give up" and start taking new steps.
I think it is fractions of a second we are talking about here. The drive will fault before that buffer is overfilled and steps lost.
Sean