My application runs very slow or locks up using

[Joe 358]

LV6 with windows NT. I have scxi 1000 with 1102,1163,1162 circut cards . Only doing 4-20 ma input and basic DIO

[Jim_Kring]

The first place I would look is to make sure that you have wait timers in all of your loops. NT can get really sluggish if you don't give the CPU a break.

-Jim

[Doug C]

Resizing arrays is another thing to lookout for. If your program is running fine then slows down to a crawl or stop, there could be a memory fragmentation issue. If your VI resizes arrays then LabVIEW alocates a new block for the large array leaving the old block empty and the fragmentation begins. I would look out for that.
Doug