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trigger for PCI-6542


I get my data from outside into this card, with an external trigger for the i/o-card. So i use the pf0-connector (SMB), by a rising edge from a external trigger i want to record the data. I need a labview program for that. Has somebody a idee??



Message 1 of 11

I use a 10 MHz clock, and the trigger goes often down. In this time the i/O-card has to stop the data record and on the next rising edge it has to start again, in the same clock cycle.



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Message 2 of 11



you want a aquisition task with retriggerable start trigger -> for that creating it in MAX (Measurement&AutomationExplorer) or with Labview Express Vi. What version do you use in Labview ? See tutorial for creating a task or the examples in labview when opening the example windows in labview and search for retriggerable (see attached *.doc file)

or the following links


Hope this helps


Best Regards




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Message 3 of 11

but i use the ni-HSDIO example vi's, so no DQM

is this possible wit this vi's?? 

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Message 4 of 11

For retriggerable HSDIO use these links:




LV example:


Best Regards

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Message 5 of 11

Hey chefcommander,


The HSDIO driver ships with example programs as well, so you might be able to find some good ideas there also. One example that sounds like it also might help you out, uses the Pause Trigger functionality of the 6542, and it is the following example called: Dynamic Acquisition Hardware Pause Depending on what you are trying to do, either the pause trigger or the Advanced Trigger with a Multi-Record acquisition that Johann pointed you to should get you started. Let us know if you have any further questions or concerns. Thanks, and have a great day.




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Message 6 of 11

THank you, thats sounds very nice. But the pause-trigger is not usefull for my problem. Ok the record start by a trigger, but i have fix packets and what is happen if the trigger goes down and the packet is not finish? so i think i can't use it.


I have a amateur question: What is the difference between multi and singel-record??





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Message 7 of 11

here is a picture how my trigger looks like.

by each rising edge of the trigger the record has to be start.

is this possible? 

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Message 8 of 11

Hey commander,


You asked the following question: "What is the difference between multi and singel-record?" 

A great resource for a lot of your questions would be the NI Digital Waveform Generator/Analyzer Help document. This help file gets installed when you install the NI HSDIO driver software, or you can download it from the following link. In the help file you can search for Records, and find the following information on the Records topic:

"A record is a group of samples. Acquired data is stored into device onboard memory as a record. When configuring an acquisition session, you can determine how many samples are stored in a record.

You can also acquire multiple unique records in a series; this process is known as multirecord acquisition. The Advance trigger initiates the acquisition of the additional records in a multirecord acquisition. The End of Record event indicates when a record acquisition is complete."


You can also search for multirecord and find the topic called Making Multirecord Acquisitions that will talk about the benefits of using a multirecord acquisition. For example the help documentation states the following:

"The main benefit of multirecord acquisitions is that you can quickly acquire numerous triggered waveforms. Multirecord acquisitions allow hardware rearming of the NI device before the data is fetched. Therefore, the rearm time, or the time when the NI device is not ready for a trigger, is extremely small, often from 1 to 100 µs, depending on the record length and the device. This short rearm time allows you to capture data whether the triggers occur microseconds or many days apart."


You don't have timing in the image of your trigger signal that you provided, so it might or might not be possible depending on how fast you are acquiring and when your triggers come in. I hope this helps. Please let us know if you have any further questions or concerns, and definitely check out the NI Digital Waveform Generator/Analyzer Help file, as it has really good information on how your device works. Thanks, and have a great day.




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Message 9 of 11

Hi THX for the answers


so i have a new picture for my problem...

by rising edge of the external hardware trigger i have to record my data. and by falling edge i have to stop, or i define a fix number of data words to record. So i use at the moment the "pause trigger-vi" with a fix number of data packets and a while loop to repeat my record and to wait for the next trigger puls. This works at the first trigger puls, but then the vi is to slow (or the while loop), the next records start after some triggers not on the second trigger puls.


Can sombody help me with this problem?





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Message 10 of 11