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Sycronizing 3rd party hardware with DAQmx in Labview

I am working on an application using LabVIEW to control a piece of external hardware while aqcuiring analog data from that hardware using DAQmx. However I am having some dificulty initiating the analog read (Analog Wfm, 1Chan NSamp). I need to send a comand to the external hardware, using the Call Library Function Node, to initiate the generation of the analog waveform data (which happens instantaneously from when the comand is recieved). I then attempt capture this waveform using an analog tigger event in DAQmx. The issue I am having though is that when I start the DAQmx task using DAQmx Read the application just sits and waits until some timeout occurs in DAQmx before moving on to the Sub VI that sends the command to the external hardware to initiate the waveform. How would I start the DAQmx task without the application waiting there for the trigger event so I can send the message to the external hardware? Is there some way of initiating the DAQmx task at the same time I send to comand to the external hardware?
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Hello ASteiner,

 

I see you are interfacing with a 3rd party data acquisition device in LabVIEW. I have a couple questions regarding the device and your application.

 

1.       What is the 3rd party data acquisition device that you are using? Is the device supported by DAQmx?

2.       You mentioned having to call an external library function to initiate the generation of your signal. Is this for specific functionality or is this because the generation is not supported by DAQmx?

3.       Is there a function call available for the analog read as well?

4.       What is the DAQmx error code that you receive when the task fails?

5.       What channel are you triggering off of and what is the timeout rate?

 

Please answer these questions as thoroughly as possible. Also, it would be helpful if you could post a screenshot of the code in question so that I can see the overall structure and flow of the application.

 

Regards,

Chris Behnke
Sr. RF Engineer
High Frequency Measurements
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First of all I have to clear up some misunderstandings about the hardware setup I am working with. It is probably my fault because my first post was admittedly a bit unclear. The 3rd party hardware is not a DAQ device, it is an RFID reader. I am using DAQmx and a NI USB-625x series DAQ to read a signal generated by the RFID reader. I have to send a command to the RFID reader using the DLLs provided by the manufacturer to initiate the signal the DAQ is triggering from and I am using the Call Library Function Node to interface with the DLLs. That hopefully answers the first two questions.

The error generated by DAQmx is Error -200284, which indicates that some or all of the samples were not acquired before the task terminated. I have done some additional work with the interface between the RFID reader analog signal and the DAQ and there seems to be some issue there that affects the DAQ's ability to sense and trigger off of the analog edge event I have set up in the code. However, if I monitor the analog out signal with an oscilloscope while attempting to run the acquisition routine, everything works flawlessly. This is leading me to think that it isn't necessarily anything wrong with the LabView code but rather a hardware issue with the connection between the DAQ and the RFID reader that I should probably post about in the DAQ forums. Perhaps there is some nuance with the terminal configuration I am unaware of that the high impedance of the oscilloscope corrects...

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Here is the screen shot of the sub-vi where the acquisition is taking place.
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