PXI

cancel
Showing results for 
Search instead for 
Did you mean: 

How can I control individual pins of VHDCI connector on PXIe-6548?

Solved!
Go to solution
Solution
Accepted by viaheaven

That's actually a cascaded error.  So basically, the configuration that Signal Express is looking for is for PFI4 to be wrapped back to PFI5.  There's a hidden error about the acquisition clock not being able to lock.  By connecting PFI4 to PFI5 you could avoid this.  This is a very simple example case.  If your system isn't clocked in this way, the play button won't work for you.

 

HOWEVER!

 

Now that we've created a HWS file with your drive and compare data, we can go back to LabVIEW (proper) and use the full capabilities to give you the ability to configure the PXIe-6548 to work with your system.

 

If you go to the Example Finder in LabVIEW in search for the keyword "compare", you should get some examples.  The one you want to start with is "Stimulus Response Load From HWS File.vi".

 

This file is documented in the code, but if your DUT is not providing a clock back to the PXIe-6548, you'll want to change the acquisition clock source to "Onboard Clock" from Strobe.

 

To make sure your acquisition session triggers, you might also set your Acquisition Start Trigger to PFI1 (which is connected to the Generation Data Active event).

 

Give that a try and let us know how it goes.

Message 31 of 34
(1,062 Views)

Thanks Keith.

 

As you said, I tried to run the "Stimulus Response Load From HWS File.vi". In the example, the data active event is exported to PFI 1. Is that necessary? Because the start trigger in acquisition session is configured as PFI 2. And then it is mentioned that an external connection between PFI1 and PFI2 is required.

 

When I run the example, I have specified dynamic channels as 0-19. Out of these 20 channels, channel 7-15 are configured for comparison. But when I see the output, i.e.. Acquired data, it shows 11 lines: plot 0, line 1 to line 10. What does this mean?

 

Is it necessary to tristate the channels 7-15 in the LabView VI although I have made them Bidirectional in the waveform itself. The example does not tristate the channels.

0 Kudos
Message 32 of 34
(1,048 Views)

Hi Keith, is it possible to use the stimulus response express VI as a normal VI? I don't want to use it through signal express. If I convert it to a standard subVI, it shows an empty front panel. Please help.

0 Kudos
Message 33 of 34
(1,004 Views)

As you said, I tried to run the "Stimulus Response Load From HWS File.vi". In the example, the data active event is exported to PFI 1. Is that necessary? Because the start trigger in acquisition session is configured as PFI 2. And then it is mentioned that an external connection between PFI1 and PFI2 is required.

 

My suggestion to change both start trigger and data active event to PFI1 is to avoid having to loop back PFI1 to PFI2.  If you don't mind doing the loopback, then you can do that as well.

 

When I run the example, I have specified dynamic channels as 0-19. Out of these 20 channels, channel 7-15 are configured for comparison. But when I see the output, i.e.. Acquired data, it shows 11 lines: plot 0, line 1 to line 10. What does this mean?

 

I would actually expect that you would see 20 channels in the waveform.

 

Is it necessary to tristate the channels 7-15 in the LabView VI although I have made them Bidirectional in the waveform itself. The example does not tristate the channels.

 

No.  By having the waveform be compare only, no data will be driven on those channels, and so the tristate VI is unnecessary.

 

Is it possible to use the stimulus response express VI as a normal VI? I don't want to use it through signal express. If I convert it to a standard subVI, it shows an empty front panel.

 

No, it's not.  However, the ExpressVI is wrapped around normal LabVIEW calls (basically it's just some fancy programming that started from our examples).  It's designed to do very specific things quickly and with a nice UI.  For more advanced and custom designs, including your own UI, you'll need to start from the examples.

 

Have you tried disconnecting your DUT and running the examples as is to see if you can get them to work on your system?

 

Thanks,

 

Keith Shapiro

National Instruments R&D

0 Kudos
Message 34 of 34
(998 Views)