# Re: howto to set the mux in usrp1

**URL:** <https://www.ruby-forum.com/t/re-howto-to-set-the-mux-in-usrp1/235023>\
**Category:** GNU Radio\
**Created:** [May 26, 2013, 12:50pm UTC](https://www.ruby-forum.com/t/re-howto-to-set-the-mux-in-usrp1/235023 "2013-05-26T12:50:50Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [May 26, 2013, 12:50pm UTC](https://www.ruby-forum.com/t/re-howto-to-set-the-mux-in-usrp1/235023/1 "2013-05-26T12:50:50Z")

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Hi josh,

thank’s for the hint - but this is not quite what I want to do:

In the future I want to use 4 separate inputs - this is for a  
network-analyzer with 2 directional couplers for S11, S21, S12, S22.  
For a start I want to use only RX-board A with 2 different signals on  
both inputs. This implies that the Q-inputs of the DDCs must be  
connected to 0.

I guess the subdev spec would be:

“A:A A:B” ?

What would be the setting to use all 4 input?

Thanks

Wolfgang

On 05/26/2013 05:00 AM, Wolfgang Buesser wrote:

> How can I control the mux in the RX-path of the usrp1?

Set the subdevice specification to “A:A B:A”. This maps the DDC0 to  
dboard A, frontend A and DDC1 to dboard B, and frontend A.

-josh

> from gnuradio.eng\_option import eng\_option
> 
> # self.head\_tx = gr.head(gr.sizeof\_gr\_complex, 1000000)
> 
> ```
> self.head_rx_0 = gr.head(gr.sizeof_gr_complex, 1000)
> 
> ```
> 
> tb = build\_block ()  
> tb.run ()
> 
> * * *
> 
> Discuss-gnuradio mailing list  
> address@hidden  
> [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)

* * *

```
                       reply via email to

```

–  
Wolfgang Buesser  
Am Ziegelberg 1a  
55595 Mandel

+49 174/585 2995  
removed\_email\_address@domain.invalid

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**Author:** ![Wolfgang\_Buesser](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/w/d9b06d/32.png) [@Wolfgang\_Buesser](https://www.ruby-forum.com/u/Wolfgang_Buesser)\
**Post date:** [May 26, 2013, 12:53pm UTC](https://www.ruby-forum.com/t/re-howto-to-set-the-mux-in-usrp1/235023/2 "2013-05-26T12:53:11Z")

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On 05/26/2013 05:49 AM, Wolfgang Buesser wrote:

> I guess the subdev spec would be:
> 
> “A:A A:B” ?
> 
> What would be the setting to use all 4 input?

A:A A:B B:A B:B

The first element is the dboard name, the second is the frontend name.  
This is the mapping for DDC0 to DDC3

-josh