Multiple applications on Same PC

Question

I am trying to run 2 applications which access different cards at the same time. One is doing a continuous analog input, the other is doing a finite analog acquisition. In that scenario, I am getting messages that either say "Acquisition already in progress" or "Unable to access Nidaq, load the driver".
I tried making a simple program that did constant reads and running them against separate cards at the same time. That worked without error, but when I shut them down and went back to the original app., it gives me "transfer is already in progress for the specified resource, or the operation is not allowed because the device is in the process of performing transfers, possibly with differn"
To answer the obvious question, yes, I
did verify that each application ws talking to a separate card.
Have you had any experience with different applications interfering with each other? This is going to be a major issue for me.
My environment is: Windows 2000, Nidaq 6.9.2, ComponentWorks 3.01, VB 6.0

Answer 1

Derek;
That is happening because you are probably doing a synchronous acquisition. When setting up a synchronous acquisition, the execution of the VI get stuck inside the AI Read.vi till the buffer of data is ready to be read.
The way to go about that is to set up two asynchronous acquisition tasks. You can get examples on that at Search Examples->I/O Interfaces->Data Acquisition->Analog Input->DAQ Occurrences.
Hope this helps.
Filipe