reading analog input and output voltage at the same time. Output of the voltage looks correct (at the rate specified), but the analog input reads in 4 at correct intervals, pauses, and goes again with 4 readings, and so on. Is this due to my VI or is it hardware realted (computer)?
Just to add a note to the great answer that has already been given:
The DAQ Assistant is an express VI that uses lower level code 'behind the scenes'(you can see this by right clicking the node and selecting 'Open Front panel'. Problems are often encountered when using multiple DAQ Asstants in a single loop, as they will execute in parallel and compete for resources. Only one can use the resource at any one time so you get this sequential behaviour.