I've been testing with a long time_spec of 2.0 seconds. The weird thing
is the device responds with an ack @ the specified 2.0 seconds that the
burst left at that time... even though it indeed when to the RFIC
immediately when the send() is called. This is on uhd 3.10 and 3.14-git.
thanks,
Mitch
On 9/30/2018 4:49 PM, Marcus Müller wrote:
Shoot, there goes my hypothesis!
But: how much time do you leave between set_time_now and then using md
in a send() call? Maybe the setting happens concurrently...
Best regards,
Marcus
On Sun, 2018-09-30 at 14:51 -0400, Mitchell J Grabner wrote:
Hi Marcus,
I use set_time_now(). For my project the devices are assumed
un-synchronized.
thanks
On 9/30/2018 1:11 PM, Marcus Müller wrote:
Hi Mitch,
this is but a shot in the blue, but:
How you're setting the device clock to 0? set_time_now() or
_next_pps(), or _unknown_pps()?
Best regards,
Marcus the other
On Thu, 2018-09-27 at 18:47 -0400, Mitchell J Grabner via USRP-
users
wrote:
I've used both 3.10.3 and 3.14 (latest git master)
double time_to_transmit = 2.0;
uhd::tx_metadata_t md;
md.start_of_burst = false;
md.end_of_burst = false;
md.has_time_spec = true;
md.time_spec = uhd::time_spec_t(time_to_transmit);
//then while loop through samples
//get burst ack
On 9/27/2018 6:32 PM, Marcus D. Leech via USRP-users wrote:
On 09/27/2018 06:27 PM, Mitchell J Grabner via USRP-users
wrote:
I set the device time stamp to zero and immediately send the
packets
to the device with a timestamp of 2.0 seconds. Also wouldn't
a
past
timestamp give late packet error?
Thanks,
Mitch
Could you show us how you're setting the metadata? (Like, the
code),
and what version of UHD you're using?
On 9/27/2018 5:25 PM, Marcus D. Leech via USRP-users wrote:
On 09/27/2018 05:02 PM, Mitch Grabner via USRP-users wrote:
Hello,
I'm trying to get a timed burst working on a B200 and it
looks like
the device is transmitting the samples the instant they
reach
the
device (tested by listening on a second device) instead
of
holding
them until the time specified in md.time_spec.
I set up the first packet's metadata with start_of_burst,
has_time_spec and give it time_spec =
uhd::time_spec_t(time_to_send); The following packets
have no
burst
metadata and the last has end_of_burst. I wait for packet
ack
with
recv_async_msg and it is received after the time
specified
in
time_spec even though the samples left immediately. There
are
no
other errors like underflow, overflow or late packets.
Has
anyone
had this issue or has any idea how to fix it? I must be
missing
something very simple.
Thanks for the help,
Mitch
Keep in mind that the time-to-send is from the perspective
of
the
device, so you have to make sure that your own flow is
synchronized to
the same time as the device.
If a packet arrives with a time specified that is in the
past,
it
gets sent immediately.
_______________________________________________
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
_______________________________________________
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
_______________________________________________
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
_______________________________________________
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
_______________________________________________
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
