Usrp_sink tx_time tag

GNU Radio
1

hi all

I’ve one more tag related question:

I want to sent packets in burst over a usrp_sink. the time between two
consecutive bursts should be 7ms. thus, I want to use a tx_time_tag
along with every first item of a packet so that the usrp waits for 7ms
before transmitting it. However, it seems that no matter what values I
send along with the tx_time tag, I always get a huge flood of “L”,
which, as far as I know, means that the sample is too late. can anybody
please enlighten me as to which values I have to transmit with the tag?
As far as I know, the value should be a tuple, with one value being the
integer part of a timestamp, the other the fractional part after the
decimal point (right?) It seems obvious that I’m sending wrong values
since I always get an “L”-flood no matter what number I transmit with
the tag.

Note: I set the time of the USRP to 0 before I run the top_block.start()
command.

kind regards,
Mat

2

Are you doing bursty transmission (i.e. using eob/sob tags, or using
tagged streams)?

M

3

Martin B. wrote in post #1177442:

Are you doing bursty transmission (i.e. using eob/sob tags, or using
tagged streams)?

M

yes, I’m using eob/sob tags. I’m assuming that the tx_time tag should be
on the same item as tx_sob?