Multifunction DAQ

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Multichannel tasks management

Hi all,

Is there any possibility to implement general usage tasks with native C only? I mean: the tasks I want to support are to be as flexible as possible. So user could define task with analog input and/or digital output. From some analysis of examples I have made it turned there were some limitations with combining channels in one task. Where should I look for these limitations?

 

I would like to have some kind of adding channel function. Generally for each channel some kind of data buffer is needed. But data exchange for one task use one combining buffer. Do I need extra functionality for combining all data buffers in one big buffer for communication with DAQ?

 

The next problem is transmitting data for continueous tasks. If we had two different channels (e.g. analog and digital) in the task, how would I know the buffer is filled/sent?

The last one is probably starting multichannel tasks. Some channels (e.g analog output) need a write function executed before start operation, but the other don't. How should I recognize the task need some operations to be done before?

 

I know these are huge issues, but I am trying to build a general access library for 6259 DAQ using only native C API with combination of C++. 

Thanks for help in advance! 

Dariusz Boczkowski 

 

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Hi

 

Sorry for such a late answer. 

 

It is not possible to create a task, which would contain both input and output channels. You also do not have to care about any memory menagement, like buffer allocation. DAQmx driver does it for You.  You can find more information in help files, which are installed together with DAQmx. Navigate to: Start->Programs->National Instruments-> NI-DAQ and You will find there "NI-DAQmx Help" and "NI-DAQmx C reference help". You should be able to find more info there. If it doesn't help You, please call us at polish toll-free support: 00 800 361 1235 (I guess You are from Poland).

 

Best regards, Maciej Antonik

Best regards,
Maciej Antonik
National Instruments Poland
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