@JHutchinson :

You might want to try using a ZPL macro to set the (x,y) location of your detector.

If you define a single Source Ray object, which represents your chief ray (let’s call it the “probe ray”), then you can use the Merit Function Editor to trace this ray and find its (x,y) intercept coordinates on the detector plane.  The ZPL macro solve then simply extracts a coordinate and applies it to the detector location.  So, you need one solve for x and a second solve for y.

The key issue to pay attention to here is the fact that multiple updates (MFE and NCE updates) are needed to make this work.  In the GUI, if you just select the “Update: All Windows” option, then it should work seamlessly.  In other words, if you perturb your system, the merit function should automatically update, which means the probe ray should automatically trace and update the solve values.  Otherwise, manual updates are needed -- the sequence is: (1) perturb the system, (2) update the merit function to get the new probe ray results, (3) update the NCE to apply these results via the ZPL solve, then lastly (4) update the merit function editor again to extract the new detector coordinates.

However, when running a tolerance analysis, you need to use a simple tolerance script to make sure the updating is done properly.  Here are examples of the ZPL macro solve (for the ray x-coordinate intercept) and the tolerance script:

Note the two GETMERIT calls (it’s not clear that the UPDATE command is required, but if not, its presence isn’t problematic).  The corresponding test model that I put together looks like this:

Here, in the Tolerance Data Editor, I simply apply an angular variation to the probe ray.  The detector now shifts in accordance with the probe ray intercept values.  

When I run a Monte Carlo tolerance analysis, the detector (x,y) shift values are reported as called for in the tolerance script:

Hope this helps...

Regards,

Jeff