LabVIEW PDA - error when running on PDA!

[sutjiptoc]

Hi, can anyone help me with tips on how to improve my program? It wouldn't run properly on the PDA... it was very slow and did not display the data properly. It also had error -200473. It's supposed to acquire data from four channels, and user should be able to choose if he/she wants the channel to be digital or analog. It also should display each channel into a graph of its own, and also display all channels in one graph. Then lastly, it should save the acquired data by writing it into a text file on the PDA.

I will show what I have done so far.. although it is just a bit of it, i think there's quite a lot of work to be done to make it run properly! Please feel free to comment on what you think I should do... I think there are other ways to do it to save memory!

[sutjiptoc]

Oh ya... for additional info, I am using DAQmx Base with a NI6004 device (Dev5). Thank you!

[Jesse_O]

Hello sutjiptoc,

I have taken a look at your code, and I have a couple of suggestions.  First, you have several task/channel in controls on your tab control (four -- one per tab).  This causes a problem since inside your while loop you try to start these 4 analog input tasks.  You cannot have more than one analog task running at a time.

I do not know how you have configured your tasks inside mxBase task configuration utility, however you will need to create a single task that has four channels.  You then only perform a single start task and DAQmx Base Read.  You can split the signal that comes out of the read and display it on your several graphs.

Regards,

Jesse O.
Applications Engineering
National Instruments

[sutjiptoc]

thank you for the suggestions! however, what if the user were to specify that he wants channel 0 to be analog, channel 1 to be digital, etc? is it possible to specify different sampling rates for each channel? from your suggestion I think it can only be either digital or analog for all four channels.

also, can the program run all 8 simultaneously (4 analog, 4 digital inputs)? or is it either analog or digital for the four channels? I have attached another program which was the first one I made, which I think is approximately what you suggested, until I had to modify it to meet a bunch of other requirements for the program. Thank you so much!