Hey Bhoomi,
First, I would like to recommend that you check out the NI 6533/6534 for NI-DAQmx Help. You might be able to find some of your answers in that help document. Now for what you are trying to do in your application, it sounds like you are only acquiring data. If this is the case, with the 6534, the device acquires data into the onboard memory as soon as the DAQmx Start Task VI runs, as long as you don't have any hardware start triggers set up. If you have a hardware start trigger, then the device will acquire after the DAQmx Start Task VI and only after you receive that hardware trigger. If you don't call the DAQmx Read VI, then the data will get stored into the onboard memory for you, as the driver handles this storing of the data into onboard memory, until the DAQmx Read VI is called, which at that point the data is transferred from the board into the computer's memory. Once you get it into computer memory, you can do whatever you would like with that data, like graph it or process it. If you take a look at the example programs (that were mentioned on how to find those in an earlier post), you can find an example that kind of shows you how this works. One of the examples you can check out is called Read Dig Port-Ext Clk.VI. In this example, it sets up to read a finite number of samples, and then starts the task. If you set up a breakpoint on the error wire after the Start VI, the data will be acquired into the onboard memory. Then when you unpause the VI, the data will be fetched from the onboard memory into system memory with the DAQmx Read VI. Again, the driver takes care of putting the data into the onboard memory for you once you start the task.
I hope this helps. Please let us know if you have any further questions or concerns regarding this issue. Also, definitely check out and try to run all of the example programs related to the 6534 so that you can learn how the hardware works, and how to use the functions to do what you want your program to do. Also make sure to read through the help on the 6534, and also the VI help documentation to learn what each function does. Thanks, and have a great day.
Regards,
DJ L.
