Using daq_in_scan() routine with USB-2404-UI

[kulkarnisoham]

I want to synchronously measure voltage applied to the 4 analog channels of the USB-2404-UI, which is seemingly possible with the daq_in_scan() routine. As a starting point, I used the example file titled DaqInScan02.py to ensure that the baseline functionality is correct. However, the UI gives the following error message "Board 0 is not compatible with this example." even when the USB-2404-UI allows simultaneous acquisition of its 4 channels. I have only one board connected and board 0 is indeed assigned to USB-2404-UI, as can be confirmed by other routines. Any help regarding this issue is appreciated.

Alternatively, I am able to use the a_in_scan() routine to collect and save data but I am not able to force this acquisition to be a simultaneous acquisition of the 4 channels. Is there a work around for achieving this using the a_in_scan() routine?

[DAQman]

The hardware design determines whether it is simultaneous, not the UL function. Some devices with daq_in_scan support don't have simultaneous analog inputs, but yours does. You can verify this by connecting the same sine wave signal to the four channels and plotting them. You will see a gap or time skew between them if they are not simultaneous.

[DAQman]

daq_in_scan() is not valid for the USB-2404-UI, instead use a_in_scan.  I have attached a Python script that records the data in a CSV file you can open with Excel, and it demonstrates using a_in_scan to read the four channels.

 

a_in_scan_file_2404.py

[kulkarnisoham]

Hi JRys,

Thank you for the response. I already have a routine that works with the a_in_scan(). However, I believe that this function does not allow simultaneous acquisition of all four channels, which is critical in my setup. Is this assumption not correct? Could you point me to the documentation that I can use to simultaneously measure the 4 channels?

Also, why does daq_in_scan() not support 2404-UI? The spec sheet does say that simultaneous acquisition is supported for frequencies up to 2 Hz.

Thank you!