cont generation of waveforms using daqmx

[samtha]

Hi,

I want to generate sine wave or any other wave using daqmx to my knowledge everything seems to be fine but there is little issue the thing is i want to vary the frequency point to point with 0.5 variation but the wave seems to clipped or distorted at (f+0.5) for example at 5Hz i get smooth sine wave but at 5.5Hz the wave seems to be distorted as seen in the attached screenshot untitled 1...........i am attaching my vi too pls give me suggestions.....thank you in advance.......

[samtha]

hi i have been trying to get the solution for the problem pls somebody give me suggestions i am out of ideas..........

[samtha]

hi i got the solution thank you...........

[samtha]

hi there for sometime it seemed that i got the solution but i didnt pls help me............sorry for the confusion.........thank you............

[Baji]

i dont know your problem is solved or not 

Its not because of the daq it bacause of your logic.

see the attached code i removed the DAQ mx Part and i simulated.

Message Edited by Baji on 08-20-2009 04:39 PM

[samtha]

Hi Bhaji,

U got my question wrong. Here i have to generate and acquire signals depending on the signal type.During runtime i need to change

the frequency as i want. Plzz help me dude.

[Baji]

What i thought is Your signal generator Vi generating the signal for one second. If your wave form data completes with the positive cycle then the next cycle also starts with positive, so you getting the two positive cycles. Thats what i tried to show in my example.

Are you getting these poblem, when changing the frequency in run time? or every second?

[samtha]

yes i get it when i change the frequency during runtime for example at 1,2,3,........10hz, the signal seems to be fine but at 1.5,2.5,

3.5....10.5hz the signal seems to be ending and starting at positive halfcycle....we have changed the # of samples in the sampling info of

function generator to 10000 and the generation rate of the daq to 20000 then everything is fine but the o/p frequency gets multiplied by 20

for ex

generated frequency=10Hz

                                   O/P RATE : 1000   ==>o/p frequency  = 10Hz

                                   O/P RATE : 10000 ==>o/p frequency= 100Hz   

                                   O/P RATE : 20000 ==>o/p frequency= 200Hz

hope u understood my problem pls check my prev vi with daq and u will understand it better thank you in advance........

Message Edited by sk_labview on 08-20-2009 11:11 PM

[Baji]

These signal generators will fix your issues.