[Discuss-gnuradio] control port problem with incorrect throttle rate

I would like some help sorting out a problem I have with control port. I have a python script that runs every second to gather the current status of control port variables. It looks like that causes the flow-graph to speed up somewhat. I set up a simple flow-graph to test it.

 

signal_source -> throttle -> probe_rate

 

I have the throttle set to 32k. If I don’t probe with my python script, the probe rate settles in close to 32k on control port monitor window. If I do have my python script running every second, then it averages about 34k but bouncing around from 33 to 35k on control port monitor window. I included my python script below.

 

Thanks.

Mark.

 

"Simplicity is prerequisite for reliability."

~ Edsger W. Dijkstra

 

-----------------------------------------

 

#!/usr/bin/python

# -*- coding: utf-8 -*-

 

import sys, os, time, struct

 

class MyApp(object):

    def __init__(self, args):

        from gnuradio.ctrlport.GNURadioControlPortClient import GNURadioControlPortClient

        program = sys.argv[0]

        hostIP = sys.argv[1]

        hostPort = sys.argv[2]

        fileName = sys.argv[3]

        GNURadioControlPortClient([program, hostIP, hostPort], 'thrift', self.store_radioclient)

        knobs_dict = self.radioclient.getKnobs([])

        f = open(fileName, 'w')

        for prop in knobs_dict:

            try:

                self.radioclient.setKnobs(self.radioclient.getKnobs([prop]))

                settable = True;

            except:

                settable = False;

            print >> f, prop, '#', settable , '#', str(knobs_dict[prop].value)

            # print prop, ' has value ', str(knobs_dict[prop].value)

        f.close()

 

    def store_radioclient(self, client):

        self.radioclient = client;

        # print '"',self.radioclient,'"'

 

if __name__ == '__main__':

    MyApp(sys.argv)

 

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