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What's meaning of "packet loss within a burst" for a USRP RIO vi?

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Dear friends, 

 

This could be a "big" question, or not a clear question.  What's meaning of the error "packet loss within a burst" ? And how to solve this error?

Here are some notes, hope could give some hints  ....  

1. I have 2 independent VI, one sender, one receiver.  there are 2 usrp rio 2943.  

2. One PC control 2 USRPS by using the Ethernet cable.

3, if I just run only one of those VIs, then I do not have any error. But If I run both at the same time, then, I got this error.   (I think, but not verified, if I run those vi with different PC (PC1 do sender, PC2 do receiver), then should be fine)

 

Thank you all for lending me a hand, and your time.  

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Hi,

 

I think the issue you're referring to is a known issue. I've linked some documentation on the error below. Basically, this error typically occurs when the PC can't write the data to the buffer fast enough so an underflow occurs. In your situation, the PC can probably handle only sending data and it can keep up with the rate required. However, when you ask it to send and receive at the same time, it puts more strain on the PC processor and it may not be able to keep up anymore. 

 

The suggested workaround is to send larger chunks of data at a time so the PC doesn't have to write to buffer as often to keep up with the hardware. Give that a try and see if that gets rid of the error. 

 

http://www.ni.com/product-documentation/14377/en/#310810_by_Date

James F.
Applications Engineer
National Instruments
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Dear James, 

 

Thanks for your help.

Allow me to ask more details. When you say, sending larger chunks of data, what do you mean by that, and how?  E.g, are you saying, each packet size should be larger?  increase the IQ rate? increase sample per symbol? Could you guide me more detail about it? Thank you!!    

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Accepted by topic author sunson29

Hi,

 

For example, if you're sending a sequence of bits 1001100, that's a very small chunk of data. Your computer has send that small chunk of data over and over very quickly so you don't encounter an underflow error from the USRP. Instead, you can just copy that sequence to make it twice as long so that your computer doesn't have to work as fast as before to keep the USRP buffer filled. So now you're sending the bit sequence 10011001001100. It's the same information, but makes it easier for the computer to keep up. 

 

James F.
Applications Engineer
National Instruments
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Thank you very much. I will try more then

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