Instrument assistant still output 0.0 without serial input, where is the trigger? - Noob question

[sunflower2772]

Guys bear with me, I am a other PLCs and VB/C programmer, there are old paradigms still locking my head.  

Refer attached vi. After i disconnected the serial input, the instrument assistant still outputs 0.0 at its terminal at regular interval about 1 hz. Now how come the inst assistant still output 0.0 without a serial input trigger? There must be a timer some where.... but I looked everywhere there is no timer including by opening the front panel of the instrument assistant. I look at the while loop block and the VISA block etc, there is no timing settings. 

So my question is, if there is no serial input to the instrument assistant, what is the object/setting that triggers the instrument assistant to still output 0.0 at a regular interval?Where is the object/setting?

 

Advance thanks 

[TCPlomp]

NEVER POST A VI WITH AUTORUNNING

The 0.0 is probably the default value (NaN would have been better), I find it kind strange that you get every second a reply, if I convert the express VI to a normal VI (with right click->open front panel) the timeout is 3000 ms so I would expect a response every 3 seconds.

Ton

[sunflower2772 · Accepted solution]

Huge huge thanks! I can sleep tonight! Muahahahahahha!