Hello Gili,
Thank you for contacting National Instruments.
It sounds like you are doing an digital output and you want to know how to set it to low (0V) when the program is done. To do this, at the end of the program write 0V or False to the digital line. There are examples of how to do this in the Example Finder (Help menu>>Find Examples). Browse Hardware Input and Output>>DAQmx>>Digital Generation>>Write Dig Chan.vi.
Please let me know if you have any questions. Have a great day!
Sincerely,
Marni S.
