measure voltage with pci-mio-16e-1 car using single trigger

[Hani R]

Hi Liming,

Sorry for the confusion.  You should connect your square wave to both ACH0 and to PFI0 / AI Start.  The hardware will monitor PFI0 for a rising slope to go above a particular level.  Once the criteria is met, the DAQmx Read VI will begin to acquire data.  Please refer to my first post with regards to how you can acquire only one square wave. 

[detech]

Sorry I do not see ACH0. My input is AI0. I connect sqwure wave to A10 and PFI0/AI start, I got the same problem.

Liming

[detech]

I copy my screen for you to check.

[detech]

I know the DQAmx trigger.vi is not working in my vi. I remove this subvi or set as non trigger. My program works. But I can not use it since I need a single trigger for capture of pulse voltage.

So how do I figure this trigger from BNC-2110?

Or BNC-2110 has no such a function, or NI PCI-MIO-16E-1 card has no trigger?

Please help

Liming 

[detech]

Hi, Hani,

Good news I figured out. I used a output signal from scope to trigger PFI 0/AI start Trig, it works. I do not know why it does not work when I input sqware wave (witch I want to measure) toPFI 0/AI. Anyway, I may leave it to understand later.

Now I try to save data in ASCI from DQAmx read.vi data output. Please can advice me to do it, I really need to finish this very quick.

Thanks

Liming  

[Hani R]

Hi Liming,

I'm glad you got the trigger working.  From the screenshot of your signal in Measurement and Automation Explorer, it looks like your signal goes from 2.4V to about 3.8V.  Essentially, the hardware is waiting for a TTL compliant signal before acquiring data to rise above 0.5V.  Because the square wave signal never crossed 0.5V, it did not trigger the acquisition to begin. 

The easiest way for you to save data to a file is to use the Write To Measurement File VI.  This is an express VI that will allow you to save to an LVM file (which can be opened by a text editor).  You can wire the data output of the DAQmx Read to the Signal input of the Write To Measurement File VI.  Let me know if you have any other questions. 

Message Edited by Hani R on 11-21-2007 10:32 AM