# Get a pointer to UHD "Source" from other block in flow graph

**URL:** <https://www.ruby-forum.com/t/get-a-pointer-to-uhd-source-from-other-block-in-flow-graph/232721>\
**Category:** GNU Radio\
**Created:** [October 23, 2014, 4:45pm UTC](https://www.ruby-forum.com/t/get-a-pointer-to-uhd-source-from-other-block-in-flow-graph/232721 "2014-10-23T16:45:02Z")\
**Posts on this page:** 1\
**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:** [October 23, 2014, 4:45pm UTC](https://www.ruby-forum.com/t/get-a-pointer-to-uhd-source-from-other-block-in-flow-graph/232721/1 "2014-10-23T16:45:02Z")

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How to get a UHD USRP SOURCE OBJECT within my own block ?

- I already instantiate an UHD USRP SOURCE in the flowgraph and I  
want a  
pointer within my own block to read parameters.
- Also, which is the effect of creating two times a new USRP SOURCE  
block by using “uhd::make(address)” with the same IP address in  
different  
blocks of the flowgraph?

I read from the manual that it is possible to control UHD Source/Sink by  
sending commands.  
In the case of Source block, are the loops admitted in GNURadio by using  
PMTs asynchronous messages for write back parameters?

Regards,  
Simone