Increasing write rate?

[ValkoA]

Hi Attique!

I assume this is the same issue you described in a different thread:

http://forums.ni.com/t5/LabVIEW/Urgent-Help-Required/m-p/2186408/highlight/false#M701770

Let's continue there!

Kind regards:

Andrew Valko

National Instruments 

[attique1987]

Hello Andrew,

Yes this is the same problem discussed in the other thread. We will continue there...

Regards 

Attique Ur Rehman

[hendyb]

Hi,

I also try to configure MIMO 2x2 system with 4 USRP 2920. I set IQ rate 200kS/sec but I have error mesages in Tx: niUSRP Write Tx Data (2D CDB).vi<ERR>Packet had timestamp that was late (or too early), and at Rx : niUSRP Fetch Rx Data (2D CDB).vi<ERR>A stream command was issued in the past.. Can you help me to solve this error messages??

In my MIMO 2x2 system, I don't use external clock. I use internal in Clock Source and Frequency Source. Is it wrong?

Thanks,

Hendy

[ErikL]

Hello Hendy -

The error you see is related to synchronization. Your command to do a simultaneous start is describing a time that has already past the current time on the inboard clock. This can be caused by setting the time base incorrectly, not resetting all clocks at the beginning of the program, or not connecting an external source when one is selected in software.

[hendyb]

Hello Mr Erik

I already implement 2x2 MIMO OFDM using USRP. I want to measure throughput of this system but I don't know how I measure it. Can you help me to solve this problem. Thanks a lot.

Regards

Hendy

[jozef.liptak]

🙂 please read the other forum post... And ask/post there, so we will keep this issue compact

[Shree_Balasubramaniam]

Hi,

I am new to the SDR field. Currently, I am developing a simple USRP Tx & Rx demo. When I increase the IQ Rate to 10M, I am receiving underflow error. What is the maximum IQ Rate we can use?

Thanks in advance!

BR
Shree