Skip to main content
Question

ZOS-API How to limit compensator ranges?

  • July 15, 2025
  • 1 reply
  • 24 views

  • Ultraviolet
  • 39 replies

EDIT TITLE: How to setup boundary constraints for custom Compensator Surface in LDE/MFE.

Hello: I am having trouble understand how to constraint a compensator surface.

Setup: I am using Surface7 as a compensator as shown below defined by MNCA, MXCA, PMGT and PMLT operands to control the boundary limits of this compensator surface variables (thickness, Decenters X&Y, Tilts in XYZ).

 

For test: I apply a DecenterX of -0.002mm on Surface3. When I execute optimization; I notice that the Optimizer can change the Compensator thickness value to go beyond the set boundary limits.

Why does this occur? How can I strictly limit the Optimizer to limit itself within the boundary limits I specify?

Thanks - Asuku

1 reply

MichaelH
Ansys Staff
Forum|alt.badge.img+2
  • Ansys Staff
  • 381 replies
  • July 15, 2025

Hmm, something doesn’t look right with the MFE (the setup looks correct but the screenshot looks incorrect).  

Did you hit refresh after modifying the MNCA row 4 operand?  It looks like you changed either the Target or the Weight column for the MNCA and you didn’t refresh the MFE.  The POPD operand has 100% of the contribution but if the MFE was refreshed, then the MNCA would have some contribution since there is a violation of the boundary operand.

Below is the excerpt from the Help Files talking about Boundary Operands.  The MNCA falls under the second possibility, so since the sum of all the violating thicknesses is greater than -0.025, there should be some % Contrib.

Also, I would suggest using CTLT & CTGT rather than MNCA/MXCA since CTLT/CTGT operate on a single surface.  Boundary Operands are confusing enough to implement properly and using ones that operate on multiple surfaces is even more difficult.  These multi-surface boundary operands were primarily designed to be used in the Default Merit Function.

If refreshing the Merit Function and using CTLT/CTGT doesn’t fix your issue, please upload a ZAR file to further help debug.


Reply


Cookie policy

We use cookies to enhance and personalize your experience. If you accept you agree to our full cookie policy. Learn more about our cookies.

 
Cookie settings