Hi Tom,
Thanks for you reply.
I am wondering why the data stream ports of byte or integer 8 could be
disconnected by other ports.
Here is an example. The connecting code is commented out, but we can run
this program without getting a error.
#!/usr/bin/env python
##################################################
# Gnuradio Python Flow Graph
# Title: Top Block
# Generated: Thu Apr 24 11:57:08 2014
##################################################
from gnuradio import blocks
from gnuradio import eng_notation
from gnuradio import gr
from gnuradio.eng_option import eng_option
from gnuradio.filter import firdes
from optparse import OptionParser
class top_block(gr.top_block):
def __init__(self):
gr.top_block.__init__(self, "Top Block")
##################################################
# Variables
##################################################
self.samp_rate = samp_rate = 32000
##################################################
# Blocks
##################################################
self.blocks_null_source_0 = blocks.null_source(gr.sizeof_char*1)
self.blocks_null_sink_0 = blocks.null_sink(gr.sizeof_char*1)
##################################################
# Connections
##################################################
#self.connect((self.blocks_null_source_0, 0),
(self.blocks_null_sink_0, 0))
# QT sink close method reimplementation
def get_samp_rate(self):
return self.samp_rate
def set_samp_rate(self, samp_rate):
self.samp_rate = samp_rate
if __name__ == '__main__':
parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
(options, args) = parser.parse_args()
tb = top_block()
tb.start()
raw_input('Press Enter to quit: ')
tb.stop()
tb.wait()
Best regards,
Damon
2014-04-23 21:46 GMT+08:00 Tom Rondeau <[email protected]>:
> On Tue, Apr 22, 2014 at 5:09 AM, Damon <[email protected]> wrote:
>
>> Hi all,
>>
>> Recently I am learning the grextras project. I am confused about the
>> message port which is designed in grextras.
>> Why will we not get a error when the message ports do not connect to
>> other message ports? I thought those port actually is data stream ports,
>> so they should be connected to other ports.
>>
>> Best regards,
>> Damon
>>
>
> Damon,
> grextras is an external project from GNU Radio and not related to the core
> functionality.
>
> But GNU Radio's message passing structure does not require connections.
> It's a publish-subscribe model, and a block will publish a message
> regardless of whether or not another block is subscribed and listening.
>
> Tom
>
>
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