# Error while running example of detect\_ff block

**URL:** <https://www.ruby-forum.com/t/error-while-running-example-of-detect-ff-block/241462>\
**Category:** GNU Radio\
**Created:** [April 8, 2015, 6:40am UTC](https://www.ruby-forum.com/t/error-while-running-example-of-detect-ff-block/241462 "2015-04-08T06:40:21Z")\
**Posts on this page:** 2\
**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:** [April 8, 2015, 6:40am UTC](https://www.ruby-forum.com/t/error-while-running-example-of-detect-ff-block/241462/1 "2015-04-08T06:40:21Z")

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hey,  
i have successfully imported “detect\_ff” block. but right now I am  
getting  
runtime error while running example on grc as follows.  
File “/home/abhishek/top\_block.py”, line 84, in   
tb = top\_block()  
File “/home/abhishek/top\_block.py”, line 53, in **init**  
self.howto\_detect\_ff\_0 = howto.detect\_ff(100, 16, 1500)  
AttributeError: ‘module’ object has no attribute ‘detect\_ff’

> > > Done  
> > > It seems there is some problem with my class name in .cc file, but i am  
> > > not  
> > > getting what exactly it is. Please help me out with this.  
> > > i have attached .cc, .xml file and also screen shot of given example is  
> > > provided

Any help will be appreciated,  
Thanks in advance,  
Abhishek

---

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**Author:** ![abhishek](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/7ba0ec/32.png) [@abhishek](https://www.ruby-forum.com/u/abhishek)\
**Post date:** [April 8, 2015, 7:00am UTC](https://www.ruby-forum.com/t/error-while-running-example-of-detect-ff-block/241462/2 "2015-04-08T07:00:16Z")

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In your .xml file, the line:

howto.detect\_ff($pfa, $L, $samples)

should be:

howto.howto\_detect\_ff($pfa, $L, $samples)

Ron