# Out of Tree Block Not Showing up in GRC

**URL:** <https://www.ruby-forum.com/t/out-of-tree-block-not-showing-up-in-grc/240915>\
**Category:** GNU Radio\
**Created:** [May 6, 2014, 4:01pm UTC](https://www.ruby-forum.com/t/out-of-tree-block-not-showing-up-in-grc/240915 "2014-05-06T16:01:29Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\
**Post date:** [May 6, 2014, 4:01pm UTC](https://www.ruby-forum.com/t/out-of-tree-block-not-showing-up-in-grc/240915/1 "2014-05-06T16:01:29Z")

</div>

I have two out of tree blocks I want to add to GRC, everything compiles  
and  
installs correctly except for the GRC component (not shown in GRC). So  
this  
should be an XML issue and I think it is related to my attempts at  
making a  
drop down option choice concerning the detection of white space/closed  
frequencies and verbose output. My XML is attached below and you can see  
that under Params Desired Detection and Verbose have options.

When I look at other stock GNU Radio block’s XML like the low pass  
filter,  
I see that some params have opt tags. Do I need these also, if so how  
would  
I use them in my case?

Thanks,

Jon

---

<div class="post-metadata">

**Author:** ![jfaulkenberry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@jfaulkenberry](https://www.ruby-forum.com/u/jfaulkenberry)\
**Post date:** [May 6, 2014, 4:48pm UTC](https://www.ruby-forum.com/t/out-of-tree-block-not-showing-up-in-grc/240915/2 "2014-05-06T16:48:18Z")

</div>

Update to my problem.

I went back into the XML and comment out my trouble sections with the  
options and rewrote them as

 Desired Detection white\_space True bool Verbose verbose false bool

Only the sink will show up in GRC.

Then I commented out all of those sections and both blocks will show up.  
Problem is I need those two variables. What am I doing wrong with my  
XML?

Jon

---

<div class="post-metadata">

**Author:** ![jfaulkenberry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@jfaulkenberry](https://www.ruby-forum.com/u/jfaulkenberry)\
**Post date:** [May 6, 2014, 5:09pm UTC](https://www.ruby-forum.com/t/out-of-tree-block-not-showing-up-in-grc/240915/3 "2014-05-06T17:09:49Z")

</div>

Take a look at:

> <https://github.com/BogdanDIA/gr-dvbt/blob/master/grc/dvbt_inner_coder.xml>

Ron

---

<div class="post-metadata">

**Author:** ![jfaulkenberry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@jfaulkenberry](https://www.ruby-forum.com/u/jfaulkenberry)\
**Post date:** [May 6, 2014, 8:57pm UTC](https://www.ruby-forum.com/t/out-of-tree-block-not-showing-up-in-grc/240915/4 "2014-05-06T20:57:09Z")

</div>

Thanks for the response, I was looking at the opt tags and I am still  
confused about how to do it. Do I need to set it up like this:

specsense.energy\_detector\_sink\_f($vlen, $eta, $white\_space.val,  
$samp\_rate, $cntr\_freq, $verbose)

 Desired Detection white\_space bool Open Band True val:True Closed Band False val:False Verbose verbose bool Yes True val:True No False val:False 

Thanks,

Jon

---

<div class="post-metadata">

**Author:** ![jfaulkenberry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@jfaulkenberry](https://www.ruby-forum.com/u/jfaulkenberry)\
**Post date:** [May 7, 2014, 9:33am UTC](https://www.ruby-forum.com/t/out-of-tree-block-not-showing-up-in-grc/240915/5 "2014-05-07T09:33:17Z")

</div>

Order of XML tags matters, check grc/python/block.dtd.

Martin

---

<div class="post-metadata">

**Author:** ![jfaulkenberry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@jfaulkenberry](https://www.ruby-forum.com/u/jfaulkenberry)\
**Post date:** [May 7, 2014, 2:08am UTC](https://www.ruby-forum.com/t/out-of-tree-block-not-showing-up-in-grc/240915/6 "2014-05-07T02:08:41Z")

</div>

Here’s an even more basic example that doesn’t use  
the opt tag. It shows my complete cluelessness about  
xml, but it works.

> <https://github.com/drmpeg/gr-dvbs/blob/master/grc/dvbs_puncture_bb.xml>

Ron

---

<div class="post-metadata">

**Author:** ![jfaulkenberry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@jfaulkenberry](https://www.ruby-forum.com/u/jfaulkenberry)\
**Post date:** [May 7, 2014, 8:53pm UTC](https://www.ruby-forum.com/t/out-of-tree-block-not-showing-up-in-grc/240915/7 "2014-05-07T20:53:27Z")

</div>

After some perusing, I think the XML for the meta file sink provided a  
good  
example. Although thanks for the previous examples, it probably took all  
three to figure it out.

Thanks again,

Jon