NI I/O Trace VISA Open question

[Rob_L2]

Hello,

I have a big application which has quite a few threads (timed while loops). One of the while loops is communicating on a specific COM port with a timed wait of 100 ms. This is the only loop which uses this specific COM port. When I look at NI I/O Trace, I see VISA Opens to this COM port every 2 ms. I have NI MAX closed. I tried changing my timed wait to 5000 ms but it had no effect.  I am trying to see if something is slowing down my application and would like to reduce these number of calls. Is NI MAX or something else trying to communicate via this COM port?

Thanks

[Queue-tip]

In IO Trace, if you navigate Tools >> Options >> View Selection, you can select the ProcessID and ThreadID Column headers to see which process and thread the calls are being made from.

Also, to verify the results of IO Trace, you could run a Portmon scan while the application is running.

'Portmon for Windows v3.03'

https://technet.microsoft.com/en-us/library/bb896644.aspx