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Very Quick PF Input Question

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Hello.
 
A quick question if I may. I am in diffs.
What are/When to use the PF inputs?
With regard to triggering data aquistiions, will wiring a +5V input to pfi0 work as a trigger?
 
Thanks.
 
 
 
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Message 1 of 13
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Thomas,
 
What daq device are you using?  If it supports ttl then using a 5v signal as a trigger should be alright.  Generally speaking you can use PFI lines for things like starting, stopping, and pausing acquisition or generation, script triggers, etc.  Look in the help files of your device to see specifically what the PFI lines can be used for in your device and for type of signals it uses.  Hope this helps.
 
Brian
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Message 2 of 13
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Hello Brian. Thanks for the reply.
 
I am using a 6071 card.
 

PFI 0/AI START

PFI 1/REF TRIG

Perhaps I should be using the PFI 1 port?
 
Here is the link for the pdf of 6071
 
 
Best Regards
 
Thomas
 
 
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Message 3 of 13
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Hi Thomas,

I have never used the 6071 so I am not 100% sure of what its capable of.  Maybe if you post an explanation of exactly what you are trying to do either I or someone who has used the 6071 before can give more specific information.  Also look in the NI-DAQ and NI-DAQmx help files that should be in the NI-DAQ folder on your computer if you have already installed NI-DAQ.

Good Luck
Brian

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Hello again.

Unfortunaely I am out of the lab for a few days, and I will not be back in until next week. So I cannot post any code.

But basically I want to start acquiring a finite amount of data from 3 AI channels.

I was thinking of using the Acq&Graph Voltage-Int Clk-Dig Ref.vi from the examples.It uses the PFI ports as a trigger. I have +5V when true, 0V when false signal that I would like to use as the trigger.

 

Thanks Again

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Message 5 of 13
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The 6071 has PFI0 as the digital trigger by default. PFI pins are very flexible and it is possible to route these digital signals internally on the board to suit your needs, although there isn't any point for you application.

I would recommend looking for a better example such as Acq&Graph Voltage-Int Clk-Dig Start.vi (shipping example)as from what you have said, this example is what you are after. Let me know if different and supply a more detailed explanation.
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Hi.

This example you mentioned triggers on a rising digital edge from PFI0.

What I am trying to do is to either use and external 5V true signal, 0V false or an internal labview true, in order to start the task.

For example can the task be triggered using one of the digital I/O ports instead of the pfi ports?

 

 

 

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Message 7 of 13
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Yes you can, but this is exactly the same as triggering from a pfi line.

PFI lines are digital lines, exactly the same as any of the DIO available. Maybe we're getting confused with the terminlogy, but I can't see why the example I mentioned cannot be used?
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*it can also be configured to trigger on falling edge.
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This example, can be used.

I have tried using this example with the external hardwired signal appplied to PFI0, and the acquisition does not start.

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