PXI 5661 Start Trigger

[crueger]

Hello folks.

I have a Problem with triggering my PXI 5661. I'm programming in C# and use the AUX I/O Input on PFI0 to trigger my Acquisiton.
I have created a method where i configure the trigger type and things which are needed for Acquisition:

public void init ()
           {
            nirfsa.SetInt32(niRFSAProperties.StartTriggerType, DigitalEdge);
            nirfsa.SetString(niRFSAProperties.DigitalEdgeStartTriggerSource, Pfi0Str);
            int trigger = nirfsa.ConfigureDigitalEdgeStartTrigger(Pfi0Str, RisingEdge);
            }  

I want to do an IQ Acquisiton in another Method. the Problem is the Acquisition is made aonly once when the Start trigger Rising Edge is asserted and then it's stopps.
the general idea to do this is doing it in a loop, i know. But how can i say to the device that every time on the PFI0 line a Rising Edge is detected it shoul do an Acquisiton?

any Ideas?? thanks
Christian

[Wetzer]

Hello crueger

To implement the designated functionality for your PXI 5661 module you have to configure a "Advance Digital Edge" Trigger instead of a "Digital Edge Start" Trigger. In Addition i suggest to use Multirecord IQ fetch instead of Singlerecord Fetch, but that depends on your Application. In Summary the following Steps have to be performed:

-Initialize Device
-Configure Aquisition Type
-Configure Reference Level
-Configure IQ Carrier Frequency
-Configure IQ Rate
-Configure Number of Samples
-Configure Trigger [Advance Digital Edge]
-Initiate [within the Loop]
-Fetch IQ [within the Loop ]
-Close [after the Loop]

[crueger]

Hello.

Thanks for your help. I solved the problem using the Digital Edge Start Trigger. The Measurement Program works fine until i want to stop the Acquisition.

There I have the problem that i can't stop the Acquisition when no trigger appears. I test the Measurement Program  with a Function Generator which sends every second for example 100 trigger impulses (100 Hz). If i switch of the Trigger within the Acquisiton and then want to stop the Acquisition it doesn't work because the device is waitin until the next trigger.

I tried to solve the problem with calling the function DisableStartTrigger() but this doesn't work.

Does anyone have an idea how i can treat especially how i can solve this problem?

thanks Christian 

[crueger]

After some days if solved the problem. I called the Abort() function of the NIRFSA and after the Timeout the Acquisiton stopps.