Triggered Acquisition

[TWB2]

I have a PCI 6014 and I am using LabWindows/CVI. I want to start acquiring data when an analog input crosses a threshold voltage, then stop when it crosses a different threshold. I'm not sure where to begin.

[RobertoBozzolo]

Unfortunately your card doesn't integrate hardware analog triggering facilities, so you must use software analog triggering.

I suggest you to begin studying an example that ships with CVI: the example is ai_async.prj and is located into \samples\easyio directory. This examples shows you an example of how to start an acquisition with sowtware analog triggering.

Hope this helps.
Roberto

[Kumar_Easwaran]

Hi Roberto,

I am using PCI 6221 DAQ Card. I want use the analog trigger in this. I know This card does not have the Hardware analog trigger. But I beleive I can use Software analog trigger.

In year 2000 I have done with PCI 6023E card.  I don't know how to do it in M series card.

Hope you can help me out.

Reagrds,

Kumar.E

[Yardov]

Hello Kumar,

There is a shipped example to perform this. You can find it on the Example Finder browsing "Hardware Input and Output » DAQmx » Analog Measurements » Voltage" and the name is Acq&Graph Voltage -Int Clk-Analog Start w Hyst.
If you look for specific triggering method, this document can give you much more ideas: Tips and Techniques in Data Acquisition Triggering - NI-DAQmx

This is part of new online documentation on DAQmx, from easy task to the more advance features used in several programming languages.
Hope this helps,