Accurate Reversals with Encoder

[MogaRaghu]

The enclosed VI is for  reversing a Servo Drive based on angle feedback from an Encoder. Being a simple state machine, no elaboration is required.

The problem however  is the accuracy of reversals. Assuming that drive is rotatting at 60rpm, it will be  1 revolution or  360 deg per second. Or  0.36 deg per millisecond. My loop timing ( intervals between  each poll of the encoder feedback )  is 25ms. ( I cannot reduce this due to some other issues ).

Thus the maximum delay after which I will capture a reversal match is 25ms or 25 x 0.36 = 9 degrees. And this can vary as it is not synchronous with the timed loop.

I simply want to restrict this reversal error with +/- 2 degrees.

Any ideas ?

Raghunathan

[Laura F.]

This thread continues here.

[MogaRaghu]

I am not sure about the reason for  the re-direction. Maybe the idea was to avoid duplication of efforts and share the knowledge. Good. But   the question was more hardware oriented and reason why I had posted it  in this multifunction DAQ section with a copy of it in LV section.

Not sure if posting the same query in two different sections is a practice that is looked down upon within this forum. If so I am sorry.

Raghunathan

[Laura F.]

Hello Raghunathan,

We generally try to consolidate threads so that all the information is in one place which is why I posted the link to the other thread.  Please don't be too concerned.  Let us know if you have additional questions.

Thanks,

Laura

[MogaRaghu]

Hi Laura,

I guessed as  much and thats fine by me. I only wanted to make sure that I don't  create an annoyance  by doing something that is frowned upon in a forum . Thanks for the clarification.

Regards

Raghunathan