novice: NI 6534 Double-Buffered Burst Mode Handshaking Internal PCLK -- Visual C++

[biju]

http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3E77956A4E034080020E74861&p_...

Trying to understand above example (repeated for many configurations)

1. Which is the array that has the data that is to be sent out of the board? What is the meaning of the comment " The 'piBuffer' here is the circular acquisition buffer", when we are not acquiring any data into the card in this example?

2. Is there a  need to have another array that has to have the same data, (but only part of it) to make use of double buffering? If so, which is it and do we need move data from the data buffer to this 'transfer buffer' with the program?

3. Is the memory on the card to be explicity declared and writen/read anywhere in the program?

4. Is the DMA alignment required only for IBM PC-AT cards and not for PCI systems?

5. Where can I find an example for simultaneous IO using 6534 under Visual c++ in burst mode? Is it possible?

- regards,
B

[Lorne H.]

Biju,

I just wanted to let you know I am working to answer your questions.  I should have an answer to you by tommorow evening.

Lorne Hengst
Application Engineer
National Instruments

[Lorne H.]

biju,

The data which is being sent out over the buffer is the 'piHalfBuffer'.    There is no need to have multiple arrays to store the information you want to send to the double buffer.  The memory on the cards buffer is explicity written to when you use the DIG_DB_Transfer() function.  You do not need to declare the buffer, although this is setup when you initialize the card with the DIG_DB_Config() function.  You do not need to worry about DMA alignment with PCI systems.

Is there a reason you are not using the newer DAQmx driver?   Can you explain the application you are trying to create?

Thanks,
Lorne Hengst
Application Engineer
National Instruments