getting the output pulses from lab view 2011 to USB 6008

[rohandevara]

hello all.. this is rohan here..i am new to labview, i am doing a very simple VI on getting analog pulses from DAQ USB 6008 by measuring harmonic currents and comparing it with a triangle wave. i am geting the pulse. but how do i extract it out from labview? i should give those pulses to a single phase inverter i.e., IGBTs.

the problem here is..while i am connecting the output DAQ its showing an error. i am attaching the jpeg of the VI and the error..hoping  a reply soon..correct me if im wrong as i am still a novice in labview. 

[Munna232]

 As per Error Message, you’re reading 2-Channel data but writing One-channel data to DAQ. 

[rohandevara]

yeah..but how do i solve this? its clear that the samples for the input daq ought to be N-SAMPLES or CONTINUOUS. but for the output daq im unable to take continuos samples..its showing an error for evry other sample except for 1 sample on demand. so they dont match and hence dat error..!!

[Dennis_Knutson]

You simply cannot select n samples or anything other than on demand. Your DAQ is not capable off doing what you want. You must pass one sample at a time to it. Typically in an auto-indexing for loop. Since your device is software timed, you will have considerable jitter.

This discussion of a 6008 analog output had occurred numerous times.

[rohandevara]

so..whats the solution for this? if i cant get the pulse out.my project wont move an inch.. and if i keep the input daq in one sample on demand..it isnt showing any waveforms and the axis are moving at a rapid pace without showing the wave..

yes ive read the discussions on analog output..bt neither they are mentioned about the input samples..but for me the eror lies with the samples only 😞

[Dennis_Knutson]

Convert the evil dynamic data to a 1D dbl array. Wire that to a for loop with a DAQmx Write inside set for 1ch 1samp. A Wait(ms) inside the loop controls the timing. As you can see from the specs, the max rate is 150 samples per second.

[rohandevara]

Wire that to a for loop with a DAQmx Write inside set for 1ch 1samp.. can u please elaborate a bit?

[Dennis_Knutson]

No, that is as simple an explanation as I can give. You should know where the DAQmx Write is. The polymorphic selector on the bottom allows you to select the type.