first thanks for replying. But i will be more specific this time. Since i have already posted the vi i will try n explain based on that. What primarily i want is that when i doing data acquisition i change the weight parameter every time i think my voltage reading(which in this case is simulated by random number) reaches some desired value which is completely dependent on the user when he thinks that the inner loop has reached a specific value he will terminate the inner loop. Now i dont want the outer loop to terminate since i want my experiment to continue i will be adding more weight and taking a new voltage reading, so after putting a new weight i will flip the switch back again to take a new reading. Now the problem is i want the value to recorded from the inner loop when the switch is fliiped to off. Which it does fine initially but later it even when the inner loop has terminated the random number continues to generate numbers which i thought shudnt have happened since the innner loop is off and it continues to write the values in the array(which is totally junk since i just wanted one value when the switch was flipped). Can you help me with proper initialisation routines if you think property node is not gud enough.