Warning 200015 occurred at DAQmx Write (Digital Wfm 1Chan NSamp).vi:4

[ossoo]

Hi,

Attached is the VI I write. But there is a warning: Warning 200015 occurred at DAQmx Write (Digital Wfm 1Chan NSamp).vi:4

I want to use digital channel to create an output. The duty cycle change from 30% to 50% to 70%. At the same time, measure the input of another 2 channels.

Do you have any idea about this?

Thanks.

[tbob]

What is the warning message?  When the warning pops up, you can right click on the number and select Explain Error.  Or there should be text in a box below the number explaining the warning.  You may not have your waveform properly defined, missing dt (sample rate) or sample rate setting does not match waveform.  You may need to build your waveform with dt and T0 before sending into the write function.  Also, which write function gives the error, you have 2 write functions.

[RavensFan]

Why are you writing the digital data a second time when Digital Data 2 is identical to Digital Data?

[ossoo]

Sorry, I made a mistake. Digital Data 2 should be different from Digital Data. Digital Data is for duty cycle 30% and Digital Data 2 is for duty cycle 50%.

[Kyle_A.]

Hello,

The situation that you are seeing here can be identified as 'glitching'.  Glitching occurs where there is potential for previous samples in a buffer to be mixed in with newer samples written into the buffer, causing a signal output that is a mix between the old and new data you are trying to output.  In the DAQmx Help document, search for 'glitching' and you will be directed to an article which explains glitching, mentions Warning 200015 is thrown where there is a potential for this to happen, and then offers suggestions on how to work around this issue, as well as two pictures that clarifies what could happen with glitching.

This warning pops up in your application since you are writing one set of data and then writing a second set of data afterwards.  If you do not see glitching on your signal, you can modify your code to ignore this warning.  Read through the help document for suggestions on modifications that will work for your application.