usb-6251 max frequency

[DSTEG]

I'm using a NI USB-6251 and the max frequecy I can achieve on an0 or an1 is 8khz using the following settings. Is there a way to achieve a higher frequency on the analog output ports?

Config:

Oscilloscope Capture:

I reconfigured the config to try and hit 10khz and captured the following response. 

config:

Oscilloscope Capture: (before analog port flat lined)

The signal is outputted for 7ms then vanishes. 

Any Ideas how to setup the analog interface to achieve a stable 100khz sine wave? I could only create a stable 8khz wave. 

[DSTEG · Accepted solution]

To utilize higher frequencies you will either need to utilize LabVIEW or custom code. I used the example "ContGen-IntClk.c" located in "C:\Users\Public\Documents\National Instruments\NI-DAQ\Examples\DAQmx ANSI C\Analog Out\Generate Voltage\Cont Gen Volt Wfm-Int Clk" and modified two lines of code to achieve higher frequencies.

2 Modified Lines:

 1. data[i]=1*sin((double)i*2.0*PI/25.0);

 2. DAQmxErrChk (DAQmxCfgSampClkTiming(taskHandle,"",2800000.0,DAQmx_Val_Rising,DAQmx_Val_ContSamps,1000));

Waveform produced:

Thank you NI for helping me out with this. 😃

[jacox]

When you say that "to utilize higher frequencies you need LabView", does that imply that LabView signal express has bandwidth limitations? Do these limitations still exist if you use the DAQ Assist wizard in LabView full?

[DSTEG]

Hi,

I'm not using LabVIEW or any other version of it. I was testing out the DAQ with the DAQmx driver. I created a task for the analog output and was having issues achieving the desired frequency. You have more control of your signal using either LabVIEW (any version I would think) or a custom C/C++ program.