# Obtain rx\_time (to create tx\_time) in a tx flow graph with USRP **URL:** \ **Category:** GNU Radio\ **Created:** [October 15, 2014, 11:47pm UTC](https://www.ruby-forum.com/t/obtain-rx-time-to-create-tx-time-in-a-tx-flow-graph-with-usrp/232555 "2014-10-15T23:47:05Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [October 15, 2014, 11:47pm UTC](https://www.ruby-forum.com/t/obtain-rx-time-to-create-tx-time-in-a-tx-flow-graph-with-usrp/232555/1 "2014-10-15T23:47:05Z")
Hi guys, I think I have said it all in the title, any ideas how I can get create tx\_time in a transmit flow graph with a USRP UHD sink? I know that UHD source spits out rx\_time, but I don’t have a UHD source in my flow graph, and if I did how would I mux in the tag into my tx streams? Cheers! Regards, David * * * David Halls Ph.D. Research Engineer Toshiba Research Europe Limited 32 Queen Square, Bristol, BS1 4ND, UK Tel: +44 (0) 117 906 0790 * * * NOTE: The information in this email and any attachments may be confidential and/or legally privileged. This message may be read, copied and used only by the intended recipient. If you are not the intended recipient, please destroy this message, delete any copies held on your system and notify the sender immediately. Toshiba Research Europe Limited, registered in England and Wales (2519556). Registered Office 208 Cambridge Science Park, Milton Road, Cambridge CB4 0GZ, England. Web: www.toshiba.eu/research/trl