Signal Express wrong time file with NI9361 Dynamic Average Freq

[JeffBradway]

 am having an interesting problem with recoding frequency measurements to a file with SignalExpress and an NI9361. I was able to find a workaround, but here's the issue:

As in the attached SignalExpress project, I am acquiring analog voltage using a NI9234. In this case the module is in place only so that the /cDAQsim/ai/SampleClock channel exists for my next step to reference. I am also aquiring Frequency with the NI9361 in Dynamic Averaging mode using the external clock reference from the analog input step above. I then have a Save to ASCII step where I want to write a cheric ASCII file, comma delimited with Absolute Time.

Here's the rub. In this instance I only cared to record Frequency to file. But, when I did this the absolute time would count by seconds for 100 points then loop back to an earlier time and count up again. (See Test01.csv attached.) This is the same behavior as if I tried to record data using just the NI9361 without an external sample clock. 

If instead I have the Save operation grab FIRST the analog input then the frequency I will get a file with correct absolute time such as Test02.csv, attached. Even if I save frequency as the first input then voltage the problem in the time scale will come back. 

Does anyone know why this would happen? Is there a simpler way to recored buffered frequency measurements with the NI9361 and SignalExpress without recording analog data? without using an analog input module at all?

[eltico]

Hi JeffBradway,

Is it feasible for you to use the Record option? I think that Signal Express works that way. I recommend you to take a look to the examples Help -> Open Example... -> Data Logging, you can get some information from there.