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TTL trigger data aqcuisition with Labview

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3 replies to this topic

#1 ldemelo

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Posted 11 June 2015 - 08:11 AM

Hi,

 

I'm new to LabJack U6 and would like to know if it is possible to trigger the U6Pro ADC with a TTL rising edge to aqcuire voltage value through Labview.



#2 LabJack Support

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Posted 11 June 2015 - 08:13 AM

Do you want 1 scan per trigger, or a bunch?  If the latter, how fast do you want to acquire data?

 

How much latency can you tolerate between the trigger and the first scan?

 

Do you need some data from just before the trigger?



#3 ldemelo

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Posted 11 June 2015 - 08:31 AM

Hi, thanks for the quick response.

 

I would like to get a bunch of scans per trigger. I would like to acquire data in a few ms if possible, I'll be using +- 10V range and resolution index 9.

I can tolerate <5ms latency. I do not need data before the trigger.



#4 LabJack Support

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Posted 11 June 2015 - 08:09 PM

The U6 does not have a hardware way to do this (the T7 does), but you have a couple options:

 

Command-Response Hardware Trigger:  Poll a digital input or counter as fast as possible (~1ms per poll per Section 3.1), and when you see the desired event start a stream.  You can get 1ms in detecting the event, but the problem might be how long it takes to start the stream.

 

Continuous Stream with Software Trigger:  Start a stream that includes your channels of interest and the trigger signal.  In software, watch for the trigger signal and just discard data before you see the trigger signal.  This is likely your best option.




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