It depends on which hardware you are using. Could you tell which aquisition card you have used in your sysyem?

hello,

check these links:

http://digital.ni.com/public.nsf/allkb/BA775B0E445BFA79482571FE0032CCEB

https://www.youtube.com/watch?v=alHwllqoLj4

Best Regards

Hello Hiba,

maybe the example in this link will help you to come up with a pre-trigger VI. It is especially suitale for measurements such as an impact test where you are only interested in the data around the impact time.

http://www.ni.com/example/25034/en/

regards,

Rouven

http://www.ni.com/example/25034/en/

It depends on the hardware you're using, and whether it has hardware triggering features or not.

In any case, the example folder of LabView, once DAQmx has been installed, provides some good examples of both HW and SW triggers that you can use as they are, or adapt to your needs

 Nice Greeting,

Thanks all for your replay and the links you provided, 

My hardware is NI 9234 which I realize it does not support for triggering, so in order to use triggering I have to use an additional module such as NI 9205 for analog triggering and specify a threshold. The digital triggering could not be used in my case . 

Could you Please correct me if I miss understanding ?

Sincerely,                                                                                                      Hiba  

If you are using your module in cRio, then you can implement triggering in FPGA.