Generating multiple ramps problem

[Mystogan]

hi everyone, I'm trying to make multiple ramps (3 ramps here) using NI6733. But the problem is, I can't have different ramp-steps (bit-number or Bit-Zahl(x) here) between ramp 1,2,3. I believe its possible to do, but seems I missed something basic here.

thanks, Yan.

[Mystogan]

I could actually do that with 3 different tasks using NI6733. But I'd like to have only 1 task to do this, because I need them to start together at the same time. While 3 parralel tasks wouldnt work.

[CDreher99]

Hello Mystogan,

I think it is difficult to set this to your Output, if you try to change the step size there are different samples to write. You can change the size with a multiplication of the Y Value and the time step with dt Value. Please try this out, I think your Hardware will give an error.

Best regards

C.Dreher

[Mystogan]

hi,

can you explain a little bit more clearer, please? I'm not sure I understand what you try to do there.

thanks,

Yan.

[CDreher99]

Hi,

It does not work, if you want to write ramps with different count of samples. You have to build ramps with the same sample rate.

I will look for a Workaround.

Best regards

C.Dreher

[Mystogan]

hi,

maybe can I use timing module card (PXIe-6674T) to make it happen? 

regards,

Yan.

[Mystogan]

hi,

I've found this while searching (http://zone.ni.com/devzone/cda/epd/p/id/354).

This example shows how to create 2 different Analog Output Tasks.

Since there can only be one clocked analog output per board, this example has
one non-clocked (software timed) task and one clocked task running in parallel.

that means I can't generate multiple ramp's with different steps using 1 DAQ card??

regards,

Yan.

[Mystogan]

Hi everyone,

with a little bit manipulation of samples number, I've managed to generate multiple ramps using 1 task. But, to have 2 tasks parallel running (using only 1 DAQ card): ramps & a sinus wave, seems hard to realize. Is it possible?? 

thanks,

Yan.

[CDreher99]

Hi Yan,

You need to consider, that all channels must have the same Samples. For example If you have a End(Volt) = 2V and Bit-Zahl = 2 (equal to 4 Samples) you will get a Step size of 2V/(4-1)Samples = 0,66

I try to simulate the PXI 6733 and I get an error if I had different samples per channel. Why do you need different Step size?

Regards

Christian

[Mystogan]

hi christian, thanks for response.

Yes, I've realised that multiple channel with different samples per channel wouldn't be problematic if I make all channels have the same sample numbers. I'm making progress with it, and now trying to generate another sine wave at the same time from the same card. The problem is, should it be continuous (like usual sinus wave generator) or finite (like usual ramp signal). I'll try to generate them both using 1 card and see how it works.

regards,

Yan.