Hi SOERJ,
In regards to your application with the PXI-6528 are you trying to write a single Boolean to toggle a line or are you trying to write a hardware timed digital waveform as the output?
I guess a better question is, how often do you need the digital data to change on your PXI-6528 digital lines?
I ask because the two modes, 1 Sample (On Demand) and N Samples (or Continuous Samples), are using completely different processes to write data to the specified line.
1 Sample (On Demand) mode writes a single sample every iteration of a specified software loop rate.
N Samples and Continuous samples use a hardware clock to ensure a digital sample is written with precise timing.
The reason you are getting the “Missing inputs” error on the N Samples mode is because you need to provide the task with a digital waveform before the DAQmx Generate step. This ensures the digital samples are written to the buffer of the device, which in turn gives it the ability to write samples in a hardware timed fashion.
You can add a digital waveform by adding the Create Digital Step (Add Step >> Create Signal >> Create Digital Signal).
Let me know if this information helps and good luck with your application.
Sam Burhans
Senior Product Manager
National Instruments