Rif.: Finite voltage input output synchronization

[Yixiao-uncle]

Hi Community:

I slightly modified a Vi found in the Forum in order to acquire (NI9234) a voltage signal generated by an output card (NI9263) and connected to the input card; both cards are in the same chassis. 

The goal is to get data reading synchronized with data generation.

However, running the Vi I find a constant 12 ms delay in reading the sine wave generated by the output card. Furthermore, the value of the amplitude is not exactly (within the limits of the accuracy of the card) the generated amplitude.
Any suggestions for my problems?
Thank you
A

[Yixiao-uncle]

Pardon, I thought I attached the Vi

[santo_13 · Accepted solution]

Delta Sigma ADC in NI-9234 has a Digital Filter in the input that adds a delay to the signal. This is documented in the specifications,

If sampling at 51.2kS/s, your delay will be 784us

[ZYOng]

I don't think that your method of measuring the 12 ms delay is accurate. There is no way to get the actual timestamp of the first analog output. The closest value is the time when Start Task VI is called, which then you can compare with the t0 of the analog input waveform.

[Yixiao-uncle]

Yes, Santhosh, you are right.

I also performed test with different sample rates and I found delay compatibile with delay calculated from board manuale.

Thank you