How are you running this VI?
You don't have a while loop around it, so it is only going to run once. (Please don't tell me you are using the run continuously button which is only meant for debugging subVI's.)
Your DAQ assistant is set for N samples, and for 100 samples of a 1 kHz rate. That means you get 1/10th of a second at a time. And if you are rerunning this, that means it runs, collects data, stops, and restarts. You have no continuous acquisition going on.
You also have 2 DAQ assistants in there which appear to be reading the same channel. Even if they are different channels on the same device, you'll have problems because for most DAQ devices, one with throw an error once the other has already started running. Just create one DAQ assistant with multiple channels.
Better yet, I suggest checking this out. Become a DAQ Guru: Learn 10 Functions in NI-DAQmx and Handle 80% of Your Data Acquisition Applicatio...
