External trigger for Prosilica camera

[KR_2007]

Hi,

Im new to LabView. I am monitoring power spectra from an instrument and I need to capture images whenever there is a spike in the graph by sending an external trigger. I would appreciate any information in this regard.

Many thanks

[Rimasaurus]

Hi,

Welcome to the NI forums!  What instrument are you monitoring, and what communication interface will you use to communicate between the instrument, LabVIEW, and the camera?  Do you plan on graphing the power spectra, and using the camera to capture an image of the power spectra graph?  Is there any additional hardware that you are using? 

Thanks,

Rima

[KR_2007]

Hello Rima,

Thank you for your prompt response. I am depositing droplets using a piezoelectric actuator. A frequency modulated signal is applied to the PZT and using a laser-diode/ photo-multipler tube arrangement, we determine the frequency of the droplets, and thereby the power spectra. The camera is currently synchronised with the PZT signal using a pulse generator. The live video is streamed to the computer using a USB cable. But we have been observing peaks in the power spectra and wish to change our imaging system to just take images when we see the peak. Could you kindly provide some information in this regard?

Many thanks,

KR

Welcome to the NI forums!  What instrument are you monitoring, and what communication interface will you use to communicate between the instrument, LabVIEW, and the camera?  Do you plan on graphing the power spectra, and using the camera to capture an image of the power spectra graph?  Is there any additional hardware that you are using?

[iRish]

Hi KR,

If you open LabVIEW and goto your example finder (Help >> Find Examples), you can use our "Triggered Grab.vi", which will give you a framework for capturing images when your spectra peaks.  (Note:  You will need our Vision Acquisition Software to see this example)

Let me know if you need some more guidance with the example or if you have any other specific questions.

Regards,

[KR_2007]

Hello Rishi,

Thank you for your response. I am trying to monitor the data in a waveform graph and wish to capture the peaks realtime as the data is being recorded. As and when each data peak is detected, a trigger is to be sent to acquire the image. Could you kindly provide few more details as to how this could be achieved?

Many thanks,

KR

[iRish]

Hi KR_2007,

Can you please post a screenshot of your code which shows your power spectra calculation and how you are obtaining the information.  There are a few ways to do analog triggering when using our DAQmx VIs but I'm not sure we can use them for your application.  It is likely we will just have to poll your power spectra to see if the output is above a certain level and use a boolean to trigger acquisition.

Thanks