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Mystogan
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using NI PXIe 6544

Hi,

 

Im wondering how can I use NI PXIe 6544 to test chip like stated here (http://zone.ni.com/devzone/cda/tut/p/id/8715). Im pretty new with labview, and I need to program the card using labview. Anyone have idea?

Btw, the digitizer card is NI PXI 5105. Any helps are really appreciated.

 

Yan.

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Brandon_B
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Re: using NI PXIe 6544

Hello Yan,

 

I will try and make this programming process as easy as possible.  From what I can tell you are using the PXIe-6544 and PXI-5105 to characterize a DAC.  What exactly are you trying to test though?  There is a Developer Zone that can help get you started with your programming.  The example in the Dev Zone assumes that you are using an NI power supply to power your DUT, but if that's not the case there is a second version of the code that doesn't include the power supply.  We can discuss things in further detail once we find out what it is you would like to test.

 

Regards,

 

Brandon Brice

High-Speed Digital I/O Product Marketing Engineer

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Mystogan
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Re: using NI PXIe 6544

Hi Brandon,

 

thanks for your reply and the link of developer zone. I'm not using any NI power supply, so I'll take a look at the example without NI power supply.

For the time being, I think I'm going to test ADC chip using NI card. Since I'm starting from scratch with labview, I'm pretty sure I'll need loads of examples from NI Labview.

My mentor asked me to make some programs at first:

1. High speed clock to test the chip (40Mhz).

2. Decimation filter to lower the sample rates.

3. Data Acquisition

4. Ramp Signal and FFT.

I've been searching for those examples in labview examples and this forum, and I've been getting this simple programs to run (in attachment). Now I need to put all together and using the NI cards that I have to test ADC (later).

 

The problem is, I dont have idea how to put all together to test a ADC chip. The idea is:

1. making ramp signal and put it to ADC (means here to test the ADC?)

2. getting bitstream from the ADC and filtering it with decimation filter

 

Now I'm stuck with generating 40MHz clock using 6544. I've seen the example, Dynamic Generation and Acquisition Demo.vi, but I dont know what to do next. :smileysad: Can I test the clock from 6544 using oscilloscope?

The isntrument that I have here: PXIe 1082 chassis, 6544 HSDIO, 6674T timing module, 6733 analog out, 5105 digitizer.

 

Any help would be very appreciated,

Yan.

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Brandon_B
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Re: using NI PXIe 6544

Hi Yan,

 

There was a slight misunderstanding on my part.  I originally thought you were trying to characterize a digital-to-analog converter because of the HSDIO (PXIe-6544) board and the scope (PXI-5105), but now that you mentioned the analog output board (6733) I can see how you would be characterizing an ADC instead. 

 

  • How many bits is your ADC?
  • What is the maximum and minimum voltage of the ADC?

Analog

The first thing you should focus on is generating the ramp signal.  There is an example in the NI Example Finder (Help -> Find Examples) called Cont Gen Voltage Wfm-Int Clk.vi.  The way our analog output boards work is you load up a waveform (in this case it would be a ramp) onto the boards memory and then specify the sample clock rate. 

 

Digital

There is another example in the NI Example Finder called Dynamic Acquisition Hardware Start Trigger.vi.  This example will be used to read the output of the ADC with your HSDIO board.  The start trigger will be necessary to ensure that you begin acquiring your digital signal once the analog board begins generating.  The wiring configuration should look like the attached picture below.

 

I would recommend starting with the ramp and then you can work on reading the digital output from the ADC.  Please let me know if you have any quesitons.

 

Regards,

 

Brandon Brice

High-Speed Digital I/O Product Marketing Engineer

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Mystogan
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Re: using NI PXIe 6544

Hi Brandon,

 

I'm pretty sure I've been looking at those two examples that you mentioned. Just the thing is, I don't know how to "test" what I'm doing, especially with that HSDIO example. I've been 'playing' with examples: Cont Gen Voltage Wfm-Int Clk.vi and using the channel 0 from 6733 to generate signal, and using the board I'm connecting channel 0 with smb cable to 5105 channel 0 and view it using niScope EX Configured Acquisition.vi. My mentor told me about making ramp signal and constant voltage to test the chip, and I got that ramp.vi file (attached in my second post). I feel like, I think I've got some puzzles part in my hand, but I don't know how to make it "work". I don't think that I need to wait the real ADC to make the test happen? can I somehow simulate it on Labview without the real ADC hardware first?

 

About the bits. Since the card 6733 is 16 bits, I'm making my ramp signal with bits that I can control (2~16bits) with labview and generate signal with parameters that been given in ramp.vi file. I'm trying to generate such signal with 6733, but stuck. Any hints?

 

About the max and min voltage, its 0~10mV Voltage.

 

I'm just not having much experience with Labview. Few hints and helps here and there, I'm sure what I need to do is not too difficult :smileyhappy:

 

regards,

Yan

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Mystogan
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Re: using NI PXIe 6544

hi Brandon,

 

I've managed to generate the ramp using Ramp_mit_DAQ.vi,

but I'm stuck to view this ramp in niScope, is there any example how to view the ramp in niScope? And what should I do now after I got the ramp generator? :smileyfrustrated:

 

Regards,

Yan

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Mystogan
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Re: using NI PXIe 6544

Hi Brandon,

 

I think I've managed to understand better about the example that you gave from here (http://zone.ni.com/devzone/cda/tut/p/id/8218). And I've modified the code a bit on purpose, so that I can use the code with using the NI devices that I have here. Btw, since I now have to make both (ADC and DAC) high speed test modules, I need much references. 

 

But the basic problem is, how do I test (viewing) the clock signal that driven out from 6544? Can I use the digitizer to view the clock signal? I've looked at some examples with using 6544. But the best example I can get to see the clock signal is that Dynamic Generation & Acquisition-Demo.vi, which routing the clock that been generated by 6544 back to the card. 

 

regards,

yan

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Vimal_F
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Re: using NI PXIe 6544

Hello Yan

 

Yes, you can use a digitizer to view the clock. You can export the clock out of your card to a PFI line or CLK out terminal. Then use the appropriate cables or probe to view the clock on your digitizer. 

 

Thank you,

Vimal F

Applications Engineer
National Instruments
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Mystogan
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Re: using NI PXIe 6544

Hi Vimal,

thanks for your reply. Using 6544 means I need to have the SMA cable to export my clock out, which I dont have yet at the moment :smileysad: (have purchased, but not yet here)

Im just wondering, since we can programm the clock, and we can also programm the digitizer, is it possible to connect them just using Labview, without cable? I dont think its impossible, right?

Maybe by using the example Dynamic Generation and Acquisition Demo.vi I can take out the clock signal out from the HSDIO in the blockdiagram and connect it to the Digitizer?

 

Regards,

Yan

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Vimal_F
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Re: using NI PXIe 6544

Hello,

 

According to the device routes, you can only export your sample clock to DDC CLK OUT or CLK OUT terminals. So, you will have to use external wiring. You can route sample clocks through the back plane with other devices, but the reason you cannot do it for HSDIO is because of bandwidth limitations; the clock is too fast as well as the rise and fall times.

 

You can also find this in the HSDIO Help located in Start>> Programs>> National Instruments>> NI-HSDIO>> Documentation.

 

Thank you,

Vimal F

Applications Engineer
National Instruments