200061 error code encountered when frequency of pulse increased

[jsphgllwy]

Hi all,

I have encountered a problem when attempting to generate a 40kHz square pulse and send it out through the DAQ assisstant. No error occurs until the frequency is increased to above 10kHz. At the point of exceeding the supposed frequency limit, the error code:

"200016 occurred at DAQmx Write (Analog 1D Wfm NChan NSamp).vi:2" pops up.

I have investigated several channels to try and overcome this but still having no luck. The frequency of the pulse should not stretch the limits of the DAQ card so I am not considering this as an issue.

So far my investigation has led me to believe that increasing the buffer size may help but my limited LabVIEW experience has meant I have struggled to successfully alter the DAQ Assist vi.

I have attached the file for anyone interested to have a play with.

The paparameters for the tx wave I am hoping to achieve are:

Square Wave, 40kHz, 5V Amplitude, Offset: 5V, Duty Cycle 50%.

I would greatly appreciate any input on this issue as it is halting my progress and causing great annoyance!

Thanks

J

Message Edited by jsphgllwy on 02-04-2010 10:44 AM

Message Edited by jsphgllwy on 02-04-2010 10:52 AM

[Rico P]

Hi,

The sampling rate must be at;easat half the frequency. So on your front panel increase "Fs" which is in the "sampling info" cluster. If you're running at 10KHz then the, Fs must be at least 20K.

Regards,

[Rico P]

Hi again,

Also noticed you used a feedback node. Instead of using feedback nodes use shift registers (like the screen shot below). To use a shift register, connect a wire to the border of the while loop, right click the newly created tunnel and click Replace with shift register.

[jsphgllwy]

Hi Rico P

I was already aware of the sampling info requirements that you flagged in your first post; thanks for the input though. With regards to the shift register, what should be placed in the false case of the structure you created?

Regards

J

[Rico P]

Hi J,

I didn't create a new case structure, this is the same as the vi attached in your first post, it just looks different because I used the clean-up tool (press ctrl u).

Regards,

[jsphgllwy]

Hi again Rico

I have tried your suggestions and unfortunately the 200061 error continues to crop up when frequency is increased. I really do not know where to go with this!

[Rico P]

Hi J,

I just looked over my message, I think I may have said conflicting instructions. The sampling rate should be at least twice the frequency. Can you confirm that you have the sampling rate at least twice the frequency? What is the sampling rate and at what frequence as you increase does the error occur?