ON button to be active with an external signal? HOW?

[Sina90]

Ladies and Gentlemen,

I am sure this question has been asked before, however I could not find the answer for my question, so sorry if the question is repetitive.

Imagine I have code that has a ON button. So if I run the code, it will wait for the user to click on ON button to start the task. Now I want to have an external button (a simple button that can be connected to the computer via USB port)  to play the role of "ON" button. How do I find such a device and where to look? I just didn't know what to google! Such a "device" should have labview VIs so that the LabView program recognizes it.

Any help or experience would be appreciated.

Sina

[RobertoBozzolo]

Is there a reason for you to post to the Labwindows/CVI board? If you are using LabVIEW you should post in its board. 

[Layosh]

Call the callback function that is associated with the ON button, from your USB-attached code.