ACI Velocity signal

[JeffLowe]

The AutoCorrecting Interpolator (ACI) on the Acc24E3 is capable of generating a high quality velocity feedback signal. Is there any guidance or app notes on how to set this up, scaling, Encoder Table settings, and so on for using this option?

[steve.milici]

This is described in the ACC-24E3 manual in the FileDepot. See the section “Additional Data Requests” starting on page 53.

[JeffLowe]

This is described in the ACC-24E3 manual in the FileDepot. See the section “Additional Data Requests” starting on page 53.

 

Yes Steve, I have read that section of the manual, but the information contained there is insufficient for any practical application, for example: This data is to be read by the ECT, but as a velocity signal, how is that processed? Does the ECT type have enough information to understand that the data is the first derivative of position, does it try to differentiate it again? In the block diagram of the control loop it shows position is automatically passed through a 1/z-1. Is there a way to override this? Do i set the ECT do integrate this value and then allow the pos2 input differentiate it again to arrive back at velocity?

This is really worthy of an app note, or a few paragraphs in the manual to explain its application.

[steve.milici]

I will see if there are any more detailed description notes on this. The basic issue is scaling.

 

In a nutshell:

You could create a new ECT entry that uses the AdcEnc register as a source (with velocity info in it) – type=1, and integrate once. Before using it for feedback, monitor the entry’s DeltaPos value along with the DeltaPos for the standard feedback entry. This should “uncover” the scaling difference.