Data Transfers and PXI-6220

[wenyan]

I saw that there are three data transfer methods for PXI-6220. They are DMA,interrupts and programmed I/O.I found that the default transfer method of PXI-6220 is DMA.

I found following sentences in DAQmx C Reference:
Analog Input >> General Properties >> Advanced >> Data Transfer and Memory >> Data Transfer Mechanism
Data Type: int32
Description: Specifies the data transfer mode for the device.

Valid valuesDAQmx_Val_DMA 10054 Direct Memory Access. Data transfers take place independently from the application.
DAQmx_Val_Interrupts 10204 Data transfers take place independently from the application. Using interrupts increases CPU usage because the CPU must service interrupt requests. Typically, you should use interrupts if the device is out of DMA channels.
DAQmx_Val_ProgrammedIO 10264 Data transfers take place when you call an NI-DAQmx Read function or an NI-DAQmx Write function.

I am using CVI to program to read multiple channels on PXI-6220 on a high speed.
What I want know is that if I want to use INTERRUPT transfer method or PROGRAMMED I/O method, what should I do? Can I use the same program to read data?

Thanks!

[AlanArmstead]

Yes, you can use the same program. DAQmx will handle the data transfer somewhat "under the hood" so your program structure can stay the same. Keep in mind that DMA is the fastest and most effective way to transfer the data. If you are doing anything high speed, then your best bet is certainly DMA.
-Alan A.