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Relation between I/Q rate and number of samples per fetch

I am using USRP 2943, 120 MHz with 1G Ethernet. When I/Q rate is more than 1MS/s, i receive error that decrease I/Q rate or increase number of samples per fetch. What is maximum value of I/Q rate for USRP 2943 with 1G Ethernet?

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Hi, this is Kota Naito from National Instruments Japan.

 

>> What is maximum value of I/Q rate for USRP 2943 with 1G Ethernet?

 

The maximum I/Q rate of USRP 2943 is 200 MS/s as indicated by its specifications sheet below.

 

http://www.ni.com/documentation/en/usrp-software-defined-radio-reconfigurable-device/latest/specs-us...

 

And, since I and Q date contain both 16 bits per sample, 1 GHz / 32 = 31 MS/s is the maximum I/Q rate that the 1G Ethernet protocol can handle. So to answer your question, the maximum value of I/Q would be 31MS/s, which is well above your current setting -- i.e. 1 MS/s.

 

Hence, the causes to the error should not be the device itself. Rather, it would probably have to do with other tasks on your computer. When your computer is busy executing other tasks, it sometimes postpones the reading of I/Q data via the Ethernet protocol, resulting in the overflow error that you are receiving.

 

Could you see if your error remains when you run the vi, attached without any other tasks such as internet browsing, watching video clips… etc? It is a modified version of a USRP sample VI `niUSRP EX Rx Continuous Async.vi`; I deleted FFT functions that could cause the computer to postpone the reading of I/Q data as well.

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Hi, 

I am just following up with you on the error that you were receiving. How did it go? In case the error still remains, perhaps you can consider referring to the link below to enhance your data streaming performance. 

http://zone.ni.com/reference/en-XX/help/373380J-01/usrphelp/data_streaming_performance_tips/

 

Regards,

 

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