Hi Pushkar,
nice to hear you are able to talk to the device.
To graph the flow rates a simple solution might be this:
Here, the flow rates of each channel are collected in an array and the whole array is the input for the graph. But note, the values are not in absolut units! The Flow Rates are in the units of the Range Codes for every channel separately, so one cant compare them in the graph, in general (In fact, I am not even sure if the value of the VI "Read Flow" should be corrected with the GCF. Are the measured values in the example program the same as in the display of the actual device? Especially for Channel 2 where the Gas Correction Factor is not equal to one?).
To record the Flow Rates you could use the VI "Write To Measurement File" (http://zone.ni.com/reference/en-XX/help/371361D-01/lvexpress/write_lv_measurement_file/) in the same manner.
Best Regards,
clementw