ni-Scope trigger configuration ( Need to acquire more signal that out of trigger range)

[PKearth]

Hi All

I've use ni-Scope and setting the ni-Scope trigger for acquire the signal.

and the signal that I can acquired show correctly. (Image below)

But for now I need to setting for acquire more signal that out of trigger range before trigger start and after trigger stop about 200ms. (Image below)

How can I setting or configurate for acquire the whole of the signal by still refer the trigger signal?

and image below is a configuration now.

Best Regards

Patsawat K.

[User002]

Hi, @PKearth,

How can I setting or configurate for acquire the whole of the signal by still refer the trigger signal?

and image below is a configuration now.

---

Disclaimer: I have never used NI-SCOPE, so I am just working from the VI information I have found online. Hopefully I can still help.

I see two things you're trying to do:

1. Collect more data than you're currently getting
2. Collect data that occurs before your reference trigger

(I *think* that if you collect more data, it will naturally include the extra data at the end of your signal, because you're using Edge triggering. If you were using Window triggering, the recommendations would be a little different.)

If you look at the documentation for niScope Configure Horizontal Timing VI and a link on that page, Configuring the Horizontal Settings, it talks about some parameters you can change.

1. To get more data, you'll need to increase how many data points you collect.
   • You can calculate how many more samples you need for both before and after the main signal.
   • It looks like it would be roughly 400ms of samples, based on the picture of your oscilloscope.
   • I think you add that number to either "min record length" or "number of records".
   • (I would start by adding more than that amount to make sure you capture it all, then trim out how much you collect from there.)
2. To collect "pretrigger" data, you need to tell the clock where your trigger will be in your data set.
   • This is done using the "reference position" input, expressed as a percentage of your data set.
   • Using a very rough tool (MS Paint), I got pixel counts from a screenshot of your image, and it looks like your "pretrigger" data will be about 5% of your data. You should use your actual data (or at least use your actual image) to figure out what percentage to use, but you can see how I found that number in the image below.
   • 

   • (24 / 469 = 0.0512 which is about 5%)

   • Once you know the percentage of data that is "pretrigger", put it into your "reference position".

Hopefully this is enough to get you going. Let us know how it goes.

-joeorbob

P.S. You might not know this, but if you attach an actual VI, it makes it much easier to help you. It took some effort to figure out what subVIs you were using.