OK, this is alarming; could you be as nice as making a minimum piece of
code that we can run locally to reproduce? I must admit I'm more or
less in an international flight boarding line, so I might not be able
to look at this for the next 72h.

Best regards,
Marcus
On Sun, 2018-09-30 at 18:34 -0400, Mitchell J Grabner wrote:
> 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
> > > > > > > > [email protected]
> > > > > > > > 
> > > > 
> > > > 
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
> > > > > > > _______________________________________________
> > > > > > > USRP-users mailing list
> > > > > > > [email protected]
> > > > > > > 
> > > > 
> > > > 
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> > > > > > _______________________________________________
> > > > > > USRP-users mailing list
> > > > > > [email protected]
> > > > > > 
> > 
> > http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
> > > > > _______________________________________________
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> > > > > [email protected]
> > > > > 
> > 
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> > > 
> 
> 


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