Dear Haider Abbas,
you can scan two different channels at the same time with the same AI Read if your hardware device is cabable of it, e.g. you must have one A/D converter for each channel. If you have one A/D converter only and your channels are multiplexed then it won't work.
You can try running both loops indepentendly by using delays but in this case the data acquisition will not be at the same time. You have also to consider that every time you call for AI Read the DAQ card will be initialised with takes some time
Hope this will help you.
Stephan