# RX Channel Out Of Range

**URL:** <https://www.ruby-forum.com/t/rx-channel-out-of-range/239750>\
**Category:** GNU Radio\
**Created:** [March 12, 2014, 10:42pm UTC](https://www.ruby-forum.com/t/rx-channel-out-of-range/239750 "2014-03-12T22:42:47Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\
**Post date:** [March 12, 2014, 10:42pm UTC](https://www.ruby-forum.com/t/rx-channel-out-of-range/239750/1 "2014-03-12T22:42:47Z")

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Hi All,

I am using GNU Radio Companion version 3.6.2.  
When I execute a simple flowgraph (containing two blocks: USRP Source  
and  
WX GUI FFT Sink), it generates the following error:

_RuntimeError: LookupError: IndexError: multi\_usrp: RX channel  
214957620880  
out of range for configured RX frontends_

Note that when I execute a flowgraph that does not deploy USRP, it works  
fine.

Does anyone have an idea how to fix this error?  
Any help is appreciated. Thank you.

Regards,  
Azza

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**Author:** ![Azza\_Ben\_Mosbah](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e56c9b/32.png) [@Azza\_Ben\_Mosbah](https://www.ruby-forum.com/u/Azza_Ben_Mosbah)\
**Post date:** [March 13, 2014, 1:45am UTC](https://www.ruby-forum.com/t/rx-channel-out-of-range/239750/2 "2014-03-13T01:45:21Z")

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Hi Azza -

We have noticed that problem if you have copied UHD source / sinks from  
another flowgraph into the one you are using. Try deleting the UHD  
blocks  
and re-creating them in your flowgraph and see if that fixes the  
problem.

There is some bug in copying those blocks between flowgraphs in GRC, I  
think.

Cheers,  
Ben

On Wed, Mar 12, 2014 at 2:41 PM, Azza Ben Mosbah

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<div class="post-metadata">

**Author:** ![Azza\_Ben\_Mosbah](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e56c9b/32.png) [@Azza\_Ben\_Mosbah](https://www.ruby-forum.com/u/Azza_Ben_Mosbah)\
**Post date:** [March 13, 2014, 2:01am UTC](https://www.ruby-forum.com/t/rx-channel-out-of-range/239750/3 "2014-03-13T02:01:10Z")

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Hi Ben,

Actually, I didn’t copy them from another flowgraph.  
But, I noticed there is a problem with my PYTHONPATH, which generates  
this  
error. When I correct it, the execution goes well.

Thank you,  
Azza

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<div class="post-metadata">

**Author:** ![Azza\_Ben\_Mosbah](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/e56c9b/32.png) [@Azza\_Ben\_Mosbah](https://www.ruby-forum.com/u/Azza_Ben_Mosbah)\
**Post date:** [March 13, 2014, 10:50am UTC](https://www.ruby-forum.com/t/rx-channel-out-of-range/239750/4 "2014-03-13T10:50:52Z")

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On 13.03.2014 02:00, Azza Ben Mosbah wrote:

> Hi Ben,
> 
> Actually, I didn’t copy them from another flowgraph.  
> But, I noticed there is a problem with my PYTHONPATH, which generates  
> this error. When I correct it, the execution goes well.

Interesting – could you please give some details on what the problem  
was and what you did to fix it?

Martin