I have a PXI-SCXI combo chassis and iam using SCXI-1520 for my measurements,whenever any data acquisition program i run,for my first iteration it's reading a high value(i.e max limit of DAQ card of 9.99V)and after that it's reading correctly.This happens first time when i run the program.If i stop and re-run again everything is reading correctly,But if i make any configuration change and run it again it behaves differently as mentioned above.what could be the reason?