case structure daqmx

[shanky1023]

Hi Dennis.

Thanks a lot . it seems to be wworking now. And i understand how to wire in for multiple channels into a single DAQmx. I justhave 2 doubts in mind it would be great if you could clarify them for me.

1. Can we connect any number of tasks in series just the way you have done for 2 (Voltage and Temperature)  now. Can i have a series of 5 temp inputs and 5 voltage inputs all into 1 DAQmx and get a single waveform ouput ??

2. What if i need a continous real time monitoring of the data so that i could see it on the waveform. Will a while loop with a CONTINOUS SAMPLE option in the sample clock do my job ???

Sorry if the questions sound too silly. Thanks again for your efforts.

[Dennis_Knutson]

1. Yes. You would not need multiple DAQmx Create Channel functions unless the configuration is different. For example, if you add another temperature channel, you would just modify the physical channel (i.e Dev1/ai5:6).

2. A while loop with continuous samples will work.

[shanky1023]

Thanks Dennis..

I shall get back if in need of any other trouble. For now things are working the way i want them to.

Appreciate your efforts

[Dennis_Knutson]

1. Yes. You would not need multiple DAQmx Create Channel functions unless the configuration is different. For example, if you add another temperature channel, you would just modify the physical channel (i.e Dev1/ai5:6).

2. A while loop with continuous samples will work.

edit- sorry for the double post

Message Edited by Dennis Knutson on 11-30-2009 12:54 PM

[shanky1023]

Hi Dennis..

here is a small problem i face..

The Multi channel readin worked well. Previously i tried to control the output current of a NI 9265 using an input signal which was discrete digital data.

But in this new code i am trying to control 2 channels in NI 9265 to throw out the current i need which will be a function of measured voltages of channel 9205 .

 Current Source 1 is a function of voltage measured in Voltage Source 1 and similarly for 2

but i cant seem to co-relate both of them. i Just wired in the output of DAQ-mx read to DAQ-mx write which i know is actually wrong. How do i go about individually co-relating the 2 sources independently.

Attached is the code...

[shanky1023]

hi..

i tried more on this and i figured out that the  input to DAQmx write needs to be in the waveform but i cant get how to condition the voltage output before i write it into the DAQmx write ..

Also could you suggets me some reading material on how to manipulate waveform data output. The basic tutorials don deal with this in detail. Soem material could be useful.

Thanks 

[Steve_B]

Hi,

You will be able to scale your signal by first getting each waveform of interest from your array of waveforms being returned from your DAQmx Read using the Index Array primitive from the Functions Palette. You can then use the Get Waveform Components primitive to split the waveform datatype into its components. The array of Y data, t0, and dt can be manipulated for your output signal. You can build the waveform back using the new values, then build the waveforms back into an array and wire the data to your DAQmx Write VI. I performed a small modification to your VI that shows how to split the data apart and build it back again. You would need to add your data manipulation as required.

I hope this is helpful.

[shanky1023]

Thanks Steve..

I shall look into this code and get back to you. I get an understanding the logic now.. I just need to see the functions.

thanks

[shanky1023]

Hi

Ilooked into the code. i could understand the logic behind it and also the functions but when i try to run it i get an error 200561 at the DAQ-mx write. I cant figure out why there should be such an error. Tried reading up on the error but doesnt help. Can you helo me debug this error

[Steve_B]

Hi,

It sounds like your AI or AO range is configured to be outside the proper settings for your device or your data set includes values that are too large or small to be generated. The error message is not very descriptive and has been flagged to have the error message improved. I would double check your settings and also that the data set doesn't include values outside of the range of the device.