Measuring single phase ac voltage in cosim

[Rakesh9490]

Hi... I am simulating a single phase H bridge inverter. When i get the ouput to be seen in labview from multisim through the HSBC connector, I am not getting the exact one that is obtained in oscilloscope.. I have attached the files.. Any help is appreciated..

[Brian_K.]

Can you tell us more about what you seeing and what you expect?  I see signals that are toggling with 50% duty cycle at 50 Hz between a positive and negative voltage.

[Rakesh9490]

Hi... I am getting a two level inveter output in multisim scope. But when the same implemented in cosim, I am only getting the positive voltage and not the negative voltage at the output...

[Brian_K.]

I'm seeing a negative.  Is yours going to ground, or just near ground.

[Rakesh9490]

This is the correct output in multism with both positive and negative voltages..

But see below in labview,  only positive output..

[Rakesh9490]

This is the image of multisim with cosim

[Brian_K.]

Well your currents are going negative which means that the voltage should go negative.  What if you put a connector on the negative side of the variable resistor and look at the difference?

[Rakesh9490]

Still the same thing. I am only getting the positive voltage.

[Brian_K.]

The schematic you uploaded had a static resistor.  Any chance you could move back to that to tell the difference?

[Rakesh9490]

I tried... But that doesnt work... I suspect this is a bug to be fixed!