Interrupt with digital input

[Fasching_K]

Hello,

I am relative new to LabWindows.

I have a program that starts when I press a button. The program controls a motor. Now I press a button on the motor and the program should stop (Safty Stop). The button is connected to an digital input on my card (PCI Express 6343). Now I have the question how I can program the interrupt? I do not know how to do it in CVI (control the digital input everytime the program runs).

I hope someone can help me.

Best regards

[SteveD123 · Accepted solution]

The starting point must be to look at the relevent examples that NI provide:

ReadDigChan-ChangeDetection.prj

and

ReadDigChan-ChangeDetectionEvent.prj

However I must advice against using a PC as a "Safety Stop". As a general rule, PCs are completely unsuited to safety critical functions, unless you follow the relevent standard IEC 62304 to the letter. Hint: this is difficult to do with a PC. For implementing safety functions such as emergency stops and interlocks you are much better buying a specialist dedicated safety relay and following the manufacturers instructions. If possibly lethal energies (either electrical or medcanical) may be present then consult a Professional Engineer.

[Fasching_K]

Thank you for your answer. I looked through the examples. Do I have interpreted the example correctly? For my application I need two tasks. The first task generates my signal and the second task is for the digital input to look if there comes a signal over this connection. This two tasks run parallel?

For the saftey stop, thank you for the advie but it is not really a saftey stop. I have a special motor that gives me a digital signal at a defined motor current. When I reach this current I should get a signal in my interface.