# ‘class uhd::usrp::multi\_u

**URL:** <https://www.ruby-forum.com/t/class-uhd-multi-u/218277>\
**Category:** GNU Radio\
**Created:** [March 27, 2012, 4:52am UTC](https://www.ruby-forum.com/t/class-uhd-multi-u/218277 "2012-03-27T04:52:28Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\
**Post date:** [March 27, 2012, 4:52am UTC](https://www.ruby-forum.com/t/class-uhd-multi-u/218277/1 "2012-03-27T04:52:28Z")

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I want to implement some functions in uhd::usrp::multi\_usrp, and access  
these functions from gnu\_uhd\_usrp\_source. Therefore, I modify the files  
as follows:

1. multi\_usrp.hpp  
I define the function  
virtual void enable\_rx\_fhop(const bool enb, size\_t mboard = 0) = 0;

2. multi\_usrp.cpp  
void enable\_rx\_fhop(const bool enb, size\_t mboard)  
{  
…  
}

3. gr\_uhd\_usrp\_source.h  
define:  
virtual void enable\_rx\_fhop\_gr(const bool enb, size\_t mboard = 0) =  
0;

4. gr\_uhd\_usrp\_source.cc  
void enable\_rx\_fhop\_gr(const bool enb, size\_t mboard)  
{  
\_dev-\>enable\_rx\_fhop(enb, mboard);  
}

When I compile the files, I get the following error message:

gr\_uhd\_usrp\_source.cc: In member function ‘virtual void  
uhd\_usrp\_source\_impl::enable\_rx\_fhop\_gr(bool, size\_t)’:  
gr\_uhd\_usrp\_source.cc:298: error: ‘class uhd::usrp::multi\_usrp’ has no  
member named ‘enable\_rx\_fhop’  
make[5]: \*\*\* [gr\_uhd\_usrp\_source.lo] Error 1

As I said, I compiled the UHD successfully, and cannot understand why  
gr-source cannot find the functions. So, any suggestions? Thanks

Peng

---

<div class="post-metadata">

**Author:** ![Peng\_Wang](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/22d042/32.png) [@Peng\_Wang](https://www.ruby-forum.com/u/Peng_Wang)\
**Post date:** [March 27, 2012, 5:05am UTC](https://www.ruby-forum.com/t/class-uhd-multi-u/218277/2 "2012-03-27T05:05:28Z")

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On 03/26/2012 07:51 PM, Peng Wang wrote:

> ```
> }
> _dev->enable_rx_fhop(enb, mboard);
> }
> 
> ```
> 
> When I compile the files, I get the following error message:
> 
> gr\_uhd\_usrp\_source.cc: In member function virtual void  
> uhd\_usrp\_source\_impl::enable\_rx\_fhop\_gr(bool, size\_t):  
> gr\_uhd\_usrp\_source.cc:298: error: class uhd::usrp::multi\_usrp has no member  
> named enable\_rx\_fhop  
> make[5]: \*\*\* [gr\_uhd\_usrp\_source.lo] Error 1
> 
> As I said, I compiled the UHD successfully, and cannot understand why gr-source  
> cannot find the functions. So, any suggestions? Thanks

Maybe its building against an old header. Did you install multi\_usrp.hpp  
to the include path?

-josh

---

<div class="post-metadata">

**Author:** ![Peng\_Wang](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/22d042/32.png) [@Peng\_Wang](https://www.ruby-forum.com/u/Peng_Wang)\
**Post date:** [March 27, 2012, 5:53am UTC](https://www.ruby-forum.com/t/class-uhd-multi-u/218277/3 "2012-03-27T05:53:22Z")

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Thank you very much. The problem is fixed.

* * *

From: Josh B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
To: removed\_email\_address@domain.invalid  
Sent: Monday, March 26, 2012 11:04 PM  
Subject: Re: [Discuss-gnuradio] ‘class uhd::usrp::multi\_usrp’ has no  
member named xxx

Maybe its building against an old header. Did you install multi\_usrp.hpp  
to the include path?

-josh