9425

[vakost]

Hello. I am very new to LabVIEW programming.

I am using the NI 9425 with DAQmx. It is a digital input module and I continuous read the inputs (I would like to update only on input level change but it doesn't support it).

I use the DAQ assistant with these parameters:

- Acquire Signals

- Digital Input

- Port Input

I select port  0 (it is all 32 lines)

- Acquisition Mode: Continuous Samples

- Samples to Read: 1

- Rate (Hz): 3

When I create an indicator, I can see it works, although the update is not at 3 Hz, it is much slower.

What I cannot do, is give the output to individual LEDs, it needs some kind of conversion I am not familiar with.

When I am trying to put a conversion to Dynamic Data (as in picture) it does not work.

So far, two problems (slow update rate and not working with individual LEDs).

When I am not trying to do it with the DAQ assistant, I don't exactly know there right parameters to select.

You will find the pictures attached.

Thanks a lot.

[GerdW]

Hi vakost,

show the full picture (or in other words: attach your VI!) to get some answers on the 3Hz sampling rate issue.

- Get rid of the dynamic datatype, you don't need it. There are functions on the waveform palette to handle digital waveform data...

- Get rid of the DAQ assistent. There are coming example VIs with LabVIEW/DAQmx explaining basic tasks like yours...

- Do you really need 32 individual boolean indicators? Why not use a boolean array?

[vakost]

Hello and thanks for the answer.

I am attaching the vi.

- Can you suggest any other functions for me to use in order to avoid the Dynamic Datatype?

- Why do you suggest to get rid of the DAQ Assistant? I have seen and use the examples but I find that there is no difference in the simple task I want to do.

- I don't want to use a boolean array (as in a couple of the examples) because I want to arrange the LEDs in different places in my screen and the LED array only places them in one row or column.

Thank you,

Vasilis.

[GerdW · Accepted solution]

Hi vakost,

I don't have DAQmx installed on this computer so I cannot check the DAQAssistent settings...

To handle the digital waveform array you get is quite easy:

You can use IndexArray to pick any element you need.

- Using plain DAQmx functions you might read your data as boolean array right from the beginning - no conversion needed afterwards.

- You might use a cluster of booleans for the frontpanel display. So you can work on boolean arrays in the block diagram and just convert to cluster for display: