Triggering NI SCOPE on Pulse Width?

[Justin_Reina]

Can you setup trigggering for NI SCOPE based on Pulse Width like you can on traditional desktop oscilloscopes (Ex - Agilent DSO-X)?

System

• PXIe-1085 Chassis
• PXIe-8135 Comp
• PXI-5105
• I am looking to trigger off of pulse width on this card

-Justin

[Nathan-P]

No.  Currently the NI-SCOPE API does not support Pulse Width Triggering.  

With the PXIe-5171R, it has an open FPGA, so you would be able to implement a custom trigger or a trigger we don't currently support using LabVIEW FPGA.  

https://www.ni.com/en-us/shop/model/pxie-5171.html

Regards,

Nathan

[Lombrozo]

The NI scope API definitely doesn't support it.  However, NI-SCOPE is an IVI-compliant driver (for whatever that's worth).  You could attempt to use the IVI driver interface which does support a Width trigger as one of the options.

From the block diagram, Quick Drop an "IVI Scope Acquire" express VI and you'll find "Width" under the "Trigger" tab and the "Type" dropdown.  At least, that's what shows up for a generic niScope.  My guess is that if that option is missing for your specific scope, then it definitely doesn't support it.

Good luck!

[ZX81]

What capture rate are you dealing with?

I have an application that does software triggering at 10kS/s (also works up to 100kS/s).  I can't find the example I based it on, but it uses the continuous acquisition approach.  I set the sample rate, then trigger to 'Software Ref Trigger', then the property 'Fetch Relative To' to 'Read Pointer'.  In software, I can do whatever unique triggering I like.  You should pad the pre-trigger a little for the delayed response.

[HWDev]

Now we are 4 years later in the year 2019. I found that there is a width trigger available in NI-SCOPE 18.7.

https://www.ni.com/docs/en-US/bundle/ni-scope/page/width-triggers.html

Why is this option not usable for Digitizer PXI-5122?

Can it be enabled by Software Update?

Is there an other solution to trigger PXI-5122 on pulse width (e.g. 3.75 ms)?

Thanks for help.

[Claire.C]

Hi HWDev,

As this post is several years old, it will probably be helpful for you to make a new thread for your questions. When a thread is newer, it usually is able to get more visibility and allow you to get help on your questions faster.

From the initial looking at your questions, that option is not available because the functionality was only put into a small subset of newer digitizers, the PXIe-5110, PXIe-5111, and the PXIe-5112. Within our driver, there is no built-in way to do what you seem to be asking, as 18.7 is the latest version and doesn't support that for your card. I don't think there is any kind of workaround that is going to do exactly what you want, but I'd recommend making a new thread to see if anyone else has ideas on that, if you are unable to get the hardware that supports that.