Hysteresis Current Control using NI myDAQ

[keshavsew]

Hello everyone,

I need to design a current controlled DC to AC Inverter using hysteresis Band current controller technique. I am designing the controller using labview.

Here is the diagram for the principle of hysteresis band current controller.

And here is my VI:

My problem is that DAQ assistant is forcing me to send a sample of data (4000 samples in this case) rather than a single data. I was able to send stream of single data when using 'One sample per demand ' in daq assistan but the problem is that it is not outputing signals at the real frequency. I have also attached my VI and sub VI below.

Any suggestion about how i can send output stream of signal data at Daq assistant block 'Trigger' rather than a sample, and keeping the real frequency.


Thank you very much 🙂

Note: Reference Current: Simulate Signal
           Actual Current: Current/Voltage Measurement
           Output Pwm: Trigger

[Bellissima]

Hello keshavsew, 

I would consider using our DAQmx functions.  An example of how to wirte continuous analog output is included below: 

https://decibel.ni.com/content/docs/DOC-34720

You can find more examples like this in the LabVIEW help by navigating to Help >> Find Examples in LabVIEW.  

Best wishes!

[keshavsew]

Hello, 

Thank you very much for your reply. The problem with continous data, is that i need to send a sample of data (much more than one). However in my case, i need to send only one sample at a time to be able to track the current, at a rate about 50KHz. 

Is it possible?

Thank you very much

[Bellissima]

Hello keshavsew, 

It really depends on your hardware.  I didn't see it listed in your post, but I would suggest googling your device online and then looking into its manuals and specification documents for information on its limitations.  

Best wishes!

[keshavsew]

Hello Amanda,

My apologies, i forgot to mention the hardware. I am using NI myDAQ

Thank you

Regards,
Keshav

[Bellissima]

Hello keshavsew.

These are the documents I mentioned:

SPECIFICATIONS NI myDAQ

http://www.ni.com/pdf/manuals/373061f.pdf

USER GUIDE NI myDAQ

http://www.ni.com/pdf/manuals/373060f.pdf

In the first one, I think you'll find your answer.  

Regards,