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rt simultaneous signal generation

Hey there everyone,

 

i'm working with the following setup:

 

- PXIe-1062Q (Chassis)

- PXIe-8108   (Embedded Controller)

- PXIe-6361  (Card used for signal generation)

- PXI-6133    (Card used for measurement purposes)

- 2x PXI-6509 (not yet implemented)

 

The system is connected via ethernet and i'm trying to generate two simultaneos free waveforms with the AO-0 and AO-1 Outputs from the PXIe-6361,

they should start at nearly the same moment.

 

Also it has to be possible to change amplitude, frequency, phase and waveform on the fly.

 

A trigger signal should be generated every period so that the measure card "knows" when a period starts. I thought the RTSI-Bus would be well suited for this signals.

 

 

I don't want you to solve all these Issues but i seriously need a good approach to solve them, because i'm trying it sice one week to get simultaneous glitch free waveforms and it just will not work...

 

 

Thanks in advance

 

Kai T.

 

BM_Trainee

 

 

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UPDATE:

 

 

Hello again,

 

now it's possible to generate two simultaneous Waveforms which are independent according to amplitude and phaseshift. The frequency for both signals should be exactly the same so i got it wrong in the my first post.

 

As you'll see in the following pictures, everything works fine, besides one big problem:

 

AO0001.JPG

Figure 1: General Output

 

 

 

AO0002.JPG

Figure 2: 180° Phaseshift

 

 

 

AO0003.JPG

Figure 3: different amplitudes (1.5V and 0.5V) V/div are the same as before!

 

 

 

The problem i has been talking about are the pauses between each 1000 samples.

Also i have to stop the output-task so that i'm able to generate a new wave.

I have to generate Signals up to 7 kHz and maybe higher. When i tried to get this output the system crashed.

 

I'll just attach the whole project to give you a better insight in my actual program.

 

 

 

So my question is, can i somehow use a continuous sampling mode and update the values to be generated on the fly?

 

 

I think it should be possible by using the onboard DAC-FIFO but i don't know how i can utilize it.

 

 

 

Thanks in advance

 

Kai T.

 

BM_Trainee

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Hi BM_Trainee,

 

 I found these two examples, perhaps this will help:

 

1. http://decibel.ni.com/content/docs/DOC-7692

2. http://decibel.ni.com/content/docs/DOC-3457

 

Best Regards,

Lam

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