DAQmxGetWriteSpaceAvail always give me 0 Space Avail

[zhoulmnk]

I try to set up a buffer for my AO. Then I can write the chunk of the big file into the buffer.But when I use the DAQmxGetWriteSpaceAvail, the availabel space is always 0.

I am calling library in Matlab.

Here is my code.

AOBuffer_Size=10000;

AOHalfBuf_Size=AOBuffer_Size/2;

 

AOBufferSpaceAvail=uint32(0);

while

[a]=calllib(

(counter<=10)'myni','DAQmxGetWriteSpaceAvail',taskSlaveAO,AOBufferSpaceAvail_ptr)

end

[a]=calllib(

'myni','DAQmxWriteAnalogF64',taskSlaveAO,5000,0,10,DAQmx_Val_GroupByScanNumber,A_ptr,empty_ptr,reserved)

end

fclose(fid);

If someone can give explanation about my problem, I appreciate.

[a]=calllib('myni','DAQmxCfgOutputBuffer',taskSlaveAO,AOBuffer_Size)

[a]=calllib('myni','DAQmxSetWriteRegenMode',taskSlaveAO,DAQmx_Val_DoNotAllowRegen) 

AOBufferSpaceAvail_ptr=libpointer('uint32Ptr',AOBufferSpaceAvail)empty_ptr=libpointer('int32Ptr',0);reserved=libpointer('uint32Ptr',[]);

fid=fopen('C:\zhou\PhysDataAcq_v2.02\SquareWaveNew.dat','r');

A=fread(fid,[1,AOHalfBuf_Size],'double');

A_ptr=libpointer('doublePtr',A);

[a]=calllib('myni','DAQmxWriteAnalogF64',taskSlaveAO,5000,0,10,DAQmx_Val_GroupByScanNumber,A_ptr,empty_ptr,reserved)

[a]=calllib('myni','DAQmxStartTask',taskMasterDO)

[a]=calllib('myni','DAQmxStartTask',taskSlaveAO)

[a]=calllib('myni','DAQmxStartTask',taskDev1CO)

counter=1;

if (AOBufferSpaceAvail>AOHalfBuf_Size)

A=fread(fid,[1,AOHalfBuf_Size],'double')

A_ptr=libpointer('doublePtr',A);

counter=counter+1;

while

[zhoulmnk]

I am setting up a buffer for my AO. So I can write a chunk of a big file into the buffer.

But when  I execute the DAQmxGetWriteSpaceAvail, I always got availabe space equals to 0.

Here is my code. I am calling library in Matlab.

AOBuffer_Size=10000;

AOHalfBuf_Size=AOBuffer_Size/2;

AOBufferSpaceAvail=uint32(0);

end

[a]=calllib(

'myni','DAQmxWriteAnalogF64',taskSlaveAO,5000,0,10,DAQmx_Val_GroupByScanNumber,A_ptr,empty_ptr,reserved)

end

fclose(fid);

If someone knows the solution,please let me know!

Thanks!

[a]=calllib('myni','DAQmxCfgOutputBuffer',taskSlaveAO,AOBuffer_Size)

[a]=calllib('myni','DAQmxSetWriteRegenMode',taskSlaveAO,DAQmx_Val_DoNotAllowRegen)

AOBufferSpaceAvail_ptr=libpointer('uint32Ptr',AOBufferSpaceAvail);

empty_ptr=libpointer('int32Ptr',0);

reserved=libpointer('uint32Ptr',[]);

fid=fopen('C:\zhou\PhysDataAcq_v2.02\SquareWaveNew.dat','r');

A=fread(fid,[1,AOHalfBuf_Size],'double');

A_ptr=libpointer('doublePtr',A);

[a]=calllib('myni','DAQmxWriteAnalogF64',taskSlaveAO,5000,0,10,DAQmx_Val_GroupByScanNumber,A_ptr,empty_ptr,reserved)

[a]=calllib('myni','DAQmxStartTask',taskDev1CO)

[a]=calllib('myni','DAQmxStartTask',taskMasterDO)

[a]=calllib('myni','DAQmxStartTask',taskSlaveAO)

counter=1;

while (counter<=10)

[a]=calllib('myni','DAQmxGetWriteSpaceAvail',taskSlaveAO,AOBufferSpaceAvail_ptr)

if (AOBufferSpaceAvail>AOHalfBuf_Size)

AOBufferSpaceAvail

A=fread(fid,[1,AOHalfBuf_Size],'double')

A_ptr=libpointer('doublePtr',A);

counter=counter+1;

[zhoulmnk]

Sorry for posting my question too many times. But the codes always cannot show up correctly.

I attach in the attachment this time.

[GarPar]

Hi zhoulmnk-

     I wonder which version of NI-DAQmx you are using.  A very similar issue was reported with NI-DAQmx version 9.0.2 using an X-Series MultifunctionDAQ card to R&D, and we fixed it on the very next release of NI-DAQmx.  The most recent version of NI-DAQmx is version 9.2.3, found here. 

     This issue was originally reported in this discussion forum post.  I would go ahead and download NI-DAQmx 9.2.3, and then let us know if the issue still persists.  Thanks!

[GarPar]

Hi zhoulmnk-

     I wonder which version of NI-DAQmx you are using.  A very similar issue was reported with NI-DAQmx version 9.0.2 using an X-Series MultifunctionDAQ card to R&D, and we fixed it on the very next release of NI-DAQmx.  The most recent version of NI-DAQmx is version 9.2.3, found here. 

     This issue was originally reported in this discussion forum post.  I would go ahead and download NI-DAQmx 9.2.3, and then let us know if the issue still persists.  Thanks!

[zhoulmnk]

Hi Gary,

Thank you for reply.

Actually I am using version 9.2.3. The problem is still there. But my matlab version is pretty old. It is R2006a.

liming

[ZachHindes]

What DAQ card are you using?  I don't see that you mentioned that.

[zhoulmnk]

Hi,

I am using PCI 6221 right now.Thank you!

liming

[GarPar]

Hi zhoulmnk-

     Take a look at this discussion forum post.  It discusses disabling regeneration in order to use the DAQmxGetWriteSpaceAvail function.  Let us know if this helps the issue.

[zhoulmnk]

Hi,

I already saw this post and disable the regeneration. The problem is still there.

I attached my codes to see if anyone can find the problem in my codes.

Thank you!

liming