Communication problems between arduino and labview

Hi everyone, I have a little problem with my arduino Mega, the problem is that I was doing some serial projects and everything was ok, but now I am trying to do something basic like reading analog values from a potenciometer for the pin A0, in labview I elaborate de VI with necesary things, the values shows in labview for 1 second and then they dissapear, I believe that I have a problem with the arduino because I check all the pins and were good I read the monitor serie and it is ok too, I change the arduino and the communication was perfect, help me, I supose I have to reset the arduino Mega but I am not sure about the problem.

I have no clue about Labview... In Python, I open the port and wait for a little (e.g. 3 seconds) then I have to fiddle with getting the microcontroller into a state that it is expecting to receive a command. Once the command is sent I get data back. I do this in part to make sure I am working with data that was not buffered by the OS. I format the data output from the microcontroller as JSON which I can then convert into a Python object and pass that to the toys that Jupiter notebooks offer.

Thaks for your answer, I was thinking in reset the arduino vut I don't know if this would solve the problem, I need more idea about this problem and if it's necessary some examples in order to reset without danger my arduino.

Have a look at how the interface is managed in this Python - Arduino demo

Note how the Python program waits for the Arduino to reset.

You may also find useful ideas in Serial Input Basics