GPSDO Clock and multiple Rx and Tx session during single run time.

[JoeKGTRI]

Hi,

We have 8 Ettus Research USRP N200 which are all equipped with GPSDO for clock synchronization.  Each radio would be connected to its own PC with LabView or executable developed in LabView to control the radios. 

• First thing I need to be able to do is to read the clock information given by the GPS and have all 8 radio synchronize the counter at a prescribed time. 

• Once each radio counter has been synchronized, each radio would start receiving signals.  Each radio would have a different designated time (Determined by the counter) to which it would stop receiving and start transmitting for given signal for a given period of time (Also determined by the counter) than go back to receiving.  This cycle of receive, transmit, receive, and resynchronize/reset counter would have to repeat multiple times.

The only clock information I would see from the given VI blocks is the timestamp from niUSRP Fetch RX Data vi.  Is there a way for us to get the GPS time as well as the internal counter clock regardless of which session we are in. Also when I tried to reopen and reinitiate the Rx after terminating, the timestamp would not restart. 

Any help would be greatly appreciated.   Thank you.

Joe

[ErikL]

Hello Joe -

While its not a supported feature, it is possible to read the UTC timestamp from a USRP with integrated GPSDO once the EEPROM setting has been set.  Once updated the USRP automatically sets its internal time to the internal GPSDO time.  I believe the attached VI  may do part of what you are requesting.... starting an acqustion at a specified time.

To enable the eeprom setting, run the following from the windows command prompt:

...\National Instruments\NI-USRP\utilities\usrp_burn_mb_eeprom.exe --key=gpsdo --val=internal

restore original setting

...\usrp_burn_mb_eeprom --key=gpsdo --val=none

We plan to add additional features in the future.  Please contact me directly if you need more information with a private message.

Best Regards,

Erik

[JoeKGTRI]

Erik, thanks for the reply.  The labview version I have is 2009 (9.0.1) and is unable to open the VIs you posted.  Could you plase repost for a later version.  Thank you.

Joe

[Anthony_F]

Here are the files Erik posted for LabVIEW 2009