# Possible bug in gr::digital::mpsk\_receiver\_cc

**URL:** <https://www.ruby-forum.com/t/possible-bug-in-gr-mpsk-receiver-cc/239301>\
**Category:** GNU Radio\
**Created:** [February 21, 2014, 4:39am UTC](https://www.ruby-forum.com/t/possible-bug-in-gr-mpsk-receiver-cc/239301 "2014-02-21T04:39:03Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\
**Post date:** [February 21, 2014, 4:39am UTC](https://www.ruby-forum.com/t/possible-bug-in-gr-mpsk-receiver-cc/239301/1 "2014-02-21T04:39:03Z")

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GnuRadio 3.7.2.1  
OSX 10.8.5

I was setting up a flowgraph in GRC using the  
mpsk\_receiver\_cc block and encountered a problem.  
Don’t know if it is a bug in the GRC xml or a  
missing method in the block code.

In GRC, the mpsk\_receiver’s “loop\_bandwidth” parameter  
is underlined in the properties popup, indicating  
that it can be changed during runtime. I entered the  
name of a variable that was created in a Wx Slider widget.

At runtime, when I try to change the value, I get:

# ================= Traceback (most recent call last): File “/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/gnuradio/wxgui/forms/forms.py”, line 180, in \_handle def \_handle(self, event): self[INT\_KEY] = self.\_slider.GetValue() File “/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/gnuradio/gr/pubsub.py”, line 52, in **setitem** sub(val) File “/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/gnuradio/wxgui/forms/forms.py”, line 138, in \_translate\_internal\_to\_external if self.\_callback: self.\_callback(self[EXT\_KEY]) File “/Users/edwardc/Work/gnu\_radio/DAS\_Test\_01.py”, line 181, in set\_loop\_bw self.digital\_mpsk\_receiver\_cc\_0.set\_loop\_bandwidth(self.loop\_bw) AttributeError: ‘mpsk\_receiver\_cc\_sptr’ object has no attribute ‘set\_loop\_bandwidth’

I checked the code, and indeed, there is no method by any name  
for setting the loop\_bandwidth attribute.

@(^.^)@ Ed

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**Author:** ![Ed\_Criscuolo](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ac8455/32.png) [@Ed\_Criscuolo](https://www.ruby-forum.com/u/Ed_Criscuolo)\
**Post date:** [February 21, 2014, 4:39pm UTC](https://www.ruby-forum.com/t/possible-bug-in-gr-mpsk-receiver-cc/239301/2 "2014-02-21T16:39:21Z")

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On 02/21/2014 04:37 AM, Ed Criscuolo wrote:

> I checked the code, and indeed, there is no method by any name  
> for setting the loop\_bandwidth attribute.

Ed,

thanks – could you please go the extra mile and post an issue on the  
tracker?

M