Multifunction DAQ

cancel
Showing results for 
Search instead for 
Did you mean: 

How ND_SCANCLK_LINE signal used in DAQmx? Is it Hold complete event?

Solved!
Go to solution

I has migrated an old app (using NI-6013-PCI Card) to DAQmx recently, but have some trouble in working. During startup signals are configured as given below.

Select_Signal(1, ND_PFI_2, ND_IN_CONVERT, ND_HIGH_TO_LOW);
Select_Signal(1, ND_SCANCLK_LINE, ND_SCANCLK, ND_LOW_TO_HIGH);

I did migration as given below.

//Select_Signal(1, ND_PFI_2, ND_IN_CONVERT, ND_HIGH_TO_LOW);
DAQmxExportSignal(TaskHandle, DAQmx_Val_AIConvertClock, "/Dev1/PFI2");
DAQmxSetAIConvActiveEdge (TaskHandle, DAQmx_Val_Falling);

//Select_Signal(1, ND_SCANCLK_LINE, ND_SCANCLK, ND_LOW_TO_HIGH);
DAQmxExportSignal(TaskHandle, DAQmx_Val_AIHoldCmpltEvent, "/Dev1/AIHoldComplete");
DAQmxSetExportedAIHoldCmpltEventPulsePolarity(TaskHandle, DAQmx_Val_ActiveHigh);

But my application shows the data as two samples shifted left. I suppose that the acquisition was delayed.
Am I doing the correct migration or is there any thing different in DAQmx?

 

 

From NI documentations I get confused whether ND_SCANCLK_LINE is AIHoldCmpltEvent or Sample clock. Or is it sampling clock?

 

 

0 Kudos
Message 1 of 3
(3,133 Views)
Solution
Accepted by topic author johnsonpm

Similar post

 

What Is the SCANCLK Signal, and How Do I Use It?

 

Hope this helps

.......^___________________^
....../ '---_BOT ____________ ]
...../_==O;;;;;;;;_______.:/
.....),---.(_(____)/.....
....// (..) ),----/....
...//____//......
..//____//......
.//____//......
..-------
0 Kudos
Message 2 of 3
(3,071 Views)

Hi Bot,

 

 There were some confusions in mapping the signal names and terminal names from traditional NI DAQ to DAQmx. Now I am convinced and the transitions of the signal / terminal names are correct. Some terminology changes are good as it was confusing earlier. I suspected these signal routing as the cause of the issues but later I found that some other issues causing the problems in measurement. 

 

I got the answer to my question. Smiley Happy

 

Thank you very much

Johnson

0 Kudos
Message 3 of 3
(3,043 Views)