scans showing error, no dimensional information

Is the scan using find nominals from CAD?

 rikracer Much more information is needed here to determine what's happening...

• What do you mean when you say the scans don't report any information - in what way? 
  • Are the scans empty (no hits)?
  • Do they contain data but no deviation (all measured values match nominal)?
  • Do the scans contain measured data and deviation values but, when reported, their dimensions show zero - if so, what dimensions are being used (location dimension showing T values of points, legacy profile form only, legacy profile form & location, geometric tolerance profile command etc)?
• Which iterate and repierce are you referring to?
  • Iterate and repierce in the Best fit alignment dialog?
  • Iterate and repierce in a geometric tolerance profile?

Are you able to share a program containing the problem?  It would need to contain measured data and I'd need the .prg, .cad and any probe files it uses.

the scans show no information, no hit data and no profile. the report says "error" and is black on the tolerance bar. I am working remote today, I do not have a copy of the program with the measured data, but I will try to get that on Monday. I had interate and repierce checked in the geo-tol profile. this does NOT happen every time, just on occasion, which is very frustrating so I will have to run the program until it occurs. it is not a single program that does it, so it is probably something I am doing wrong, I just don't know what

I am not using find nominals it is set to nominals, not find noms

Are they DEFINED or RELEARN scans?  Defined scans follow the path that was generated and will return zero data for areas where the probe either leaves the surface or where the deflection is too high.  Relearn scans will attempt to adjust themselves to track the surface so that the probe deflection always stays within acceptable limits.

When it comes to DEFINED or RELEARN. Is it up to the programmer i.e. me. Or is there a method you recommend more over the other? It sounds like these are similar methods. So relearn will be more likely to give you all the hits you ask for and adjust for probe deflection, whereas DEFINED will ignore data due to probe deflection?

It's up to the programmer to choose the appropriate scan method for their application.  Defined scans are generally better for application where you don't expect to encounter a large amount of deviation from nominal - machined parts with less than 1mm profile tolerances to fully constrained datum reference frames for example .  Relearn scans are better for parts which are expected to deviate significantly from their nominal shape or where the location of the surface being scanned can vary.  However, because the scan essentially teaches itself as it goes, they need to run at slower scan speeds than a defined scan.

I have been using DEFINED scans as the parts have somewhat tight tolerances and are usually very close to the desired profile. I will try to post the program after the issue occurs today. I am very thankful for the dialog that is happening, thank you.