CVI - Synchronizing two AI signals using PCI-6251

[m.h.s]

Hi all,

The application which i am trying to develop with my NI PCI-6251 M-series DAQ card is to synchronize the two sine wave signals acquiring from  AI0 and AI1 respectively. The source of the first sine wave signal is Analog ouput 0 (AO 0) of the same PCI-6251 card and the second sinewave signal that i am acquiring is externally coming from function generator.Both the signals have same frequency.

The problem which i am facing is that the two signals are not synchronizing. One signal that i am generating from   AO 0 is still ( Acquiring from AI0 ) and other from function  generator is continuously rotating (Acquiring from AI1).

I am also using the ANALOG TRIGGER but synchronization is completely out.

DAQmxCfgAnlgEdgeStartTrig (*inputTaskHandle, "Dev1/ai0" , DAQmx_Val_RisingSlope, 0.0);

I have also Tried Digital Trigger like aiStartTrigger, aoStartTrigger, aiSampleClock etc but the response remains the same.

Any help will be greatly appreciated.

[Jonathan_S1]

Hi,

Could you describe what you mean by "The two signals are not synchronizing"?  Screenshots would be helpful.

Do you mean the the triggering is inconsistent?  Are you doing a finite or continuous acquisition?  It sounds like you are trying to set it up so that the acquisition will begin when the signal on channel

AI0 has a positive slope with a level of 0.  Are you seeing something other than this?

Jon