When you configured your DO task, you specified a single channel containing a single digital line -- "Dev1/port0/line0".
Apparently, wherever and however you constructed the waveform data you send to DAQmx Write, you defined your waveform to have 8 lines of data in it.
And that's the meaning of the error message. Your task contains only 1 line as a destination while your data contains 8 lines. The mismatch causes the error.
-Kevin P
CAUTION! New LabVIEW adopters -- it's too late for me, but you *can* save yourself. The new subscription policy for LabVIEW puts NI's hand in your wallet for the rest of your working life. Are you sure you're *that* dedicated to LabVIEW? (Summary of my reasons in this post, part of a voluminous thread of mostly complaints starting here).
