I am having trouble getting my PCI6713 analog output board going. I am using double buffering under Borland Builder 5.

[wapieng]

I am having trouble getting my PCI6713 analog output board going. I am following the example set out in WFMdoubleBuf.c in the Borland C++ examples, but if the "old data stop" parameter in WFM_DB_Config() is set to 1, then later when WFM_Group_Control(START) is called, NIDAQ error 10800 - "operation could not complete within the time limit" comes up. If "old data stop" is set to 0 then WFM_Group_Control(START) gives no error but the waveform takes several seconds to get going properly. I am programming one channel using an 8K ciculating buffer and a 4K transfer buffer and my sample rate is 5000sps. Has anybody run into this problem before?
NI Softw
are : Borland C++/Builder 5
NI Hardware : AO device PCI-6713
Driver Version : NIDAQ 6.9.2
Operating System : Windows NT 4.0

[wapieng]

I have discovered the answer to my own problem: Because I am using only one channel of the DAC for output, the channel vector array piChanVect[] must apparently be exactly one cell wide or you get the 10800 NIDAQ Error. Who knew?

Now I need to know why I get an underflowerror from the very first call to WFM_DB_Transfer().

[Spencer S.]

Greetings,

If you change the sizes of your buffers, does the underflow error disappear? What is the exact error code you are receiving?

One other question, have you changed the example program a great deal? What changes have you made?

Let me know, and we will find the solution.

Thanks.

Spencer S.

[wapieng]

Thanks for responding.

The error # is 10844 and no, the buffer size doesn't make any difference, nor doess the sample rate. I don't think it is a time delay or latency problem because it happens immediatly when the code tries to reload the first half buffer the very first time, (I know because I put a DIO toggle around the code and watched it on a scope). Attached is the code snippet for loading the circular buffer. It is almost like I am not getting this process started correctly or something. One difference I noted between my code and the example code is that the example does a WFM_DB_Transfer() using the same buffer as the circular buffer. Is this significant or is my concept of a "Transfer" all wet? What exactly is the WFM_DB_Transfer() f
unction doing anyway?

Thanks for any help you can give me.