USRP underflow problem for "TDMA MIMO Cable demo"?

[HustLiliAn]

Hi, everyone:    The underflow problem has confused us for a long time. Brandon has also ask a topic about this   http://forums.ni.com/t5/USRP-Software-Radio/Tx-Underflow-details/td-p/2304048 . I have the same situation with him, my purpose is to send null signal (0+0i) when I have no data to transmit ,   but if  the data ready , I need to send the data instantly.  I found the TDMA MIMO calble demo is the prototype for my project.  But  there is still the underflow problem of this demo . Can anyone give the method to solve this problem , thank you!

[HustLiliAn]

https://decibel.ni.com/content/docs/DOC-23677 , the link of the demo

[ErikL]

Please be sure you are using the 1.2 driver. Also we will take a look at the code.

[HustLiliAn]

Today, I try to run the demo again, but I found once I use the MIMO Cable to connect two different usrps, the NI-USRP Configuration Utility can't find the usrps,  if I pull out the MIMO Cable, the devices can be found again. It is strange, no matter the driver 1.1 or 1.2 have the same problem. 

[ErikL]

The mimo cable shares the ethernet connection between devices.  Please connect using the MIMO cable and disconnect one of the USRP devices from the ethernet cable.  This should resolve the issue.  Please let us know if it does not.