You don't mention what kind of card you're using. Not all of them support defining each line as input or output. E series cards have this capability while with the DIO-24 and DIO-96 cards, each line in a port must be the same. If your card does have the capability, use DIO Port Config.vi and specify the direction in the line direction map control. In your case, if line 0 is an output and all others are input, the line direction map value would be a 1. To read and write, you would then use DIO Port Read.vi and DIO Port Write.vi and set the line masks. You could also just use Write to Digital Line.vi and Read From Digital Line.vi as these call DIO Port Config and Port REad/Write. The problem is that they you can't read or write more than a single line at a tim
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There are plenty of examples in how digital I/O works in Examples>I/O Interfaces>Data Acquisition>digital Input and Output>ImmediateDigital Input and Output.
