Pulse generation

[J.Timmer]

Good afternoon!

I'm not an expert with LabView and I have some questions.

For my experiments, I will use LabView with 16 channels to measure pore pressure and MetFlow for UVP probes.

There is a BNC connector at the back plate of UVP-DUO (positive or negative, external trigger TTL signal 0-5V) and I want to connect this to my DAQ USB 6218.

What do I have to add in my block diagram in LabView to trigger the UVP's?

I attached my Vi. I tried to generate a pulse but then I can't connect to the DAQ assistant2, which I configured with digital output.

I just want one single pulse to activate everything.

Am I doing right?

Thanks in advance,

Timmer

[edjones93]

I would highly recommend to review Core 1 available to you in the online training in your NI profile if you have an active license.

From what you have created, your code will only execute once (if it could), I suggest reviewing core 1 so you are familiar with while loops and best practices so you can actually have the system read the data continuously.

With regards to DAQAssistant2, if you just need it to toggle from False to True, wire a true value constant to it, since DAQAssistance2 is set to 1 sample on demand, the output should remain true.

Best regards,

Ed

[J.Timmer]

I'm sorry but I didn't understand what you said 😕

This is the block diagram I'm using now.

Can the loop I did in the previous diagram run in here?

I will use a BNC connector (external trigger TTL signal 5V).

And yes, I just need to run once because it's only to trigger the UVPs (ultrasound velocity profile).

Timmer

[J.Timmer]

Can anyone help me please?

I attached my last Vi.

What am I doing wrong?

It doesn't work; the UVPs don't start measuring.

I just want to generate a single pulse to trigger the UVPs... 

Timmer

[cbutcher]

Perhaps you could try this VI and see hows it works? If it doesn't solve the issue, perhaps it will give some ideas. I removed all of the extra graphs and placed them in multiple plots on one graph - the index control allows you to change which plot the slide controls.

If this doesn't work for you, you can index the 2D array into multiple 1D arrays and wire them to separate graphs, with separate slides. I just thought this was simpler (especially for a demo).

[J.Timmer]

I'm very new in Labview so some things I don't understand...

Can I try something simple?

For example, create another DAQ assistant, format for digital output?

Something like this?