[Discuss-gnuradio] gr-ctrlport-monitor timeout exception

[Nowlan, Sean]

I’m using ControlPort to monitor transmissions through a USRP. I have a flowgraph responsible for generating burst traffic and streaming to a uhd_sink. Then I have a uhd_source tuned to the same frequency as the uhd_sink, and I connect it to a ctrlport_probe2_c block with length=128. I have ControlPort support compiled-in and enabled from a config file. I’m able to connect to a remotely running flowgraph using gr-ctrlport-monitor and plot the PSD of the “samples” vector pulled from the probe2 block every 100 milliseconds. The problem is that after (what seems to be) a nondeterministic time, the ICE port stops responding and gr-ctrlport-monitor reports an error:

 

ctrlport-monitor: radio.get threw exception (exception ::Ice::ConnectTimeoutException

{

}).

 

When I close and restart, gr-ctrlport-monitor times out and segfaults:

 

2013-11-11 16:02:47.329422 /usr/local/bin/gr-ctrlport-monitor: error: Traceback (most recent call last):

  File "/usr/lib/pymodules/python2.7/Ice.py", line 984, in main

    status = self.doMain(args, initData)

  File "/usr/lib/pymodules/python2.7/Ice.py", line 1031, in doMain

    return self.run(args)

  File "/usr/local/lib/python2.7/dist-packages/gnuradio/ctrlport/IceRadioClient.py", line 97, in run

    radio = self.getRadio(host, port)

  File "/usr/local/lib/python2.7/dist-packages/gnuradio/ctrlport/IceRadioClient.py", line 36, in getRadio

    radio = GNURadio.ControlPortPrx.checkedCast(base)

  File "/usr/local/lib/python2.7/dist-packages/gnuradio_ice.py", line 1257, in checkedCast

    return _M_gnuradio.ctrlport.GNURadio.ControlPortPrx.ice_checkedCast(proxy, '::GNURadio::ControlPort', facetOrCtx, _ctx)

ConnectTimeoutException: exception ::Ice::ConnectTimeoutException

{

}

 

Segmentation fault (core dumped)

 

So there are two issues to note here:

-          Something in the ICE instance is breaking on the GNU Radio flowgraph side. The port is still open; it just times out. Trying to instantiate gr-ctrlport-monitor to an incorrect port just says “connection refused,” as expected.

-          gr-ctrlport-monitor is not robust to connection-related errors like timeouts or refused connections.

 

Is there any advice of what I can turn on or enable in GNU Radio or my flowgraph to debug the first problem? I can live with the second problem as long as I can make sure ICE doesn’t break on me.

 

Thanks,

Sean