Interesting, I had not considered that. Makes sense. But ... doesn't it seem like the compiler or runtime would at least give me a warning that using @State with a class has the problem you described? Or is there a case where @State with a class is the right thing to do? Robert

Fair enough on the timeout, Quinn. I was really trying to just determine if the connection was going to work at all, or was destined to fail. Looking for the error on the .waiting state works. But I have two additional questions: Should I specifically look for NWError? Or should I look for POSIXError? Or just plain error? Is there somewhere I can read how to do this without asking on the forum? Is there a record of the "lore" as it pertains to the Network Framework that I can study? Thanks again for the help! Robert

Well, I think I will just create a 32-bit floating point buffer in the first place. I was hoping I was just missing a function definition somewhere (like vImageConvert_16UtoF). By the way, I had a second question buried in my post (sorry about that). What does the parameter "histogram_entries" represent in the vImageContrastStretch_PlanarF() method? It says it is the "number of histogram entries". Do I just pick a number? Or does it represent the number of unique pixel values in my data? Thanks, Robert