Synchronized Output of PCI 6220 and 6711

[EESteve1992]

Hello All,

I am attempting to use one PCI 6220 and two PCI 6711 boards to accurately output synchronized signals with microsecond precision.  The boards are all connected via a RTSI cable.  Currently, I believe I have a good setup for writing digital signals to the board, however I am running into a lot of troubles trying to create accurate analog signals.  The program sometimes returns an error saying DAC conversion attempted before data to be converted was available.  I think this error comes from the fact that the program is trying to run more DAC than it should have to.  I think I need to setup a prgram that writes digital signals, but for the analog uses timed updates from a trigger.  This will cut down on the info that needs to be fed into the buffer.  Any suggestions on how this could be implemented would be very helpful.

Thank you,

Steve

LabVIEW 2011 SP1

Microsoft Window 7

[NetoNI]

Hello EESteve 1992,

Could you attach a screenshot of the error.

Also could you be more specific about what do you mean with having trouble creating accurate analog signals.

Where is the DAQmx Trigger.vi? How are you triggering this?

Meanwhile, I think you could use our examples at LabVIEW Help/Find Examples.. then on the window that opens you can take a look at hardware input and output folder/DAQmx. There you can find lots of very useful examples. I do not know if you were aware of this resource, but it is pretty useful, so I just wanted to share it with you.

Regards

Ernesto

[EESteve1992]

Hi NetoNI,

Thanks for the reply. I have since figured out what was wrong with the inaccurate analog signals, (simple array arrangement issue) but now I have encountered a bigger problem.  When running the program I receive an error stating Memory is full.  I will attach this screenshot. I'm not really sure what the best path to correct this is.  i'm sure there are multiple ways to go about it but I'm trying to find the most efficient way to go about this. 

Would it be possible to trigger the analog changes off of a digital line? Or is there a more efficient way to transfer the analog data to the board without overloading the memory? Is it possible to add external memory to the 6711 board?     

[NetoNI]

Hello EESteve 1992, 

No, it is not possible to add external memory to the NI PCI-6711. 

Yes, I think you could use digital triggers to control Analog tasks if the specifications of your selected card say it is supported. 

The following link has information about triggering. It says M series, but the important thing is the concepts. Those concepts apply to any of our cards. 

M Series Synchronization with LabVIEW and NI-DAQmx
http://www.ni.com/white-paper/3615/en/

Hope this helps you out with your work. 

Regards

Ernesto