I am working on a test machine that has 3 operator push button controls. The controller are all wired to a NI 9421 digital module. Two of the controls are push buttons on the front of the machine that will apply a 12 VDC signal to ports 1 "start" and 2 "reverse" of the 9421 when operator depresses the control. Port 0 "stop" will have 12 VDC applied, except when there is a break in a light curtain. I want to monitor these ports during the runnning of the vi to change the state in the vi when there is a change. How do I get a boolean output from each of these ports so I can change the state of the machine?
