I need to generate square signal by using NI PCI-6533(PCI-DIO-32HS) DAQ card.Can I do that with this hardware.

[David S.]

Hi Sachinj -

The PCI-6533 is a digital input and output board.  It is designed to generate digital signals, which are trains of pulses.  As a pulse is a square signal, you can, in a sense, generate a square signal using this device.  You won't be able to change the voltage level of the output, but you can change the pulse duration and delay using the NI-DAQmx driver.

[Sach]

Hello David

Thanks for your reply. I got that square signal can be generated by using PCI-DIO-32HS card, as it is a digital card.

Is there any .vi file in the database of NI which I can use to generate the continuous square signal.?

If not can you suuggest any .vi file which I can modify to get the square signal.?

Sachin

Message Edited by Sachinj on 10-31-2006 04:08 PM

Message Edited by Sachinj on 10-31-2006 04:09 PM

[David S.]

Hi Sachin -

I've attached a slightly modified copy of the Cont Write Dig Pot-Ext Clk.vi example program that can be found in LabVIEW's Example Finder.  The only changes I made were to specify the Onboard Clock as the sample clock source (since this feature is supported on your board) and increase the number of samples in the buffer to 16 (since this is the minimum number of samples allowed by your board).  If you have any questions about it, please let me know!

[Sach]

Thanks for the modified program Cont Write Dig Port-Ext Clk (6533).vi. I checked this vi.program in LabVIEW 8.2. I think this program is based by using pattern hgeneration which I tried earlier but without success.

And for square signal which I want ,I need to change the frequency and phase of the signal.I think I can't do this in current .vi file. Please guide me to achieve this in current file?.

Sachin

[David S.]

Hi Sachin -

The 6533 isn't designed as a pattern generator, and so it lacks many of the features you're looking for.  It is meant to be a digital communication device.  It lacks the feature to adjust phase (or offset from the sample clock).  You can adjust generation frequency by simply changing the sample clock rate, which is a connector on the front panel of the VI.

I recommend that you consider using one of our function generators instead.  These devices are deisgned specifically to the task you describe, and they carry every feature you've requested.

If you plan to continue using your DAQmx-based device, I recommend checking out our new Getting Started with DAQmx page. It's been categorized and expanded to teach both basic information and advanced techniques.  It's a great resource when the Help documentation and shipping examples aren't quite enough.

[Danielkks]

Hello David,

Came across your post in my search which is pretty close to my application.

Can i control the number of pulses to generate through this HW?

Daniel

[David S.]

Hi Daniel -

Sure you can.  In fact, you can do so with any DAQmx Task based on Sample Clock timing.  All you have to do is specify the Sampling Mode as "Finite Samples" instead of "Continuous Samples".

You can learn more about this and a lot of basic DAQmx programming techniques in the Getting Started link I posted above.  There's more information in the NI-DAQmx Help file, which is found on your computer's Start menu.  (Look under Programs » National Instruments » NI-DAQ.)