# Eye diagram error **URL:** \ **Category:** GNU Radio\ **Created:** [February 17, 2015, 6:32pm UTC](https://www.ruby-forum.com/t/eye-diagram-error/234231 "2015-02-17T18:32:06Z")\ **Posts on this page:** 7\ **Page:** 1
**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:** [February 17, 2015, 6:32pm UTC](https://www.ruby-forum.com/t/eye-diagram-error/234231/1 "2015-02-17T18:32:06Z")
Hello, When I used eye diagram block (which seems to be a member of WxGUI class), the following error appeared: File “/usr/local/lib/python2.7/dist-packages/baz/eye.py”, line 98, in **init** self.st = gr.message\_sink(gr.sizeof\_float, msgq, dont\_block=1) AttributeError: ‘module’ object has no attribute ‘message\_sink’ what is the main problem? best, Mostafa ---
**Author:** ![mostafa\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/5e9695/32.png) [@mostafa\_a](https://www.ruby-forum.com/u/mostafa_a)\ **Post date:** [February 17, 2015, 7:11pm UTC](https://www.ruby-forum.com/t/eye-diagram-error/234231/2 "2015-02-17T19:11:03Z")
Hi Mostafa, which GNU Radio version are you using? GNU Radio itself (to my knowledge) doesn’t come with a dedicated eye diagram, and it’s possible that you’re trying to use an out-of-tree module that was meant for another version of GNU Radio. You can try to emulate an eye diagram by using the Scope Sink, and triggering on a signal that has an edge on every symbol center. Best regards, Marcus ---
**Author:** ![mostafa\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/5e9695/32.png) [@mostafa\_a](https://www.ruby-forum.com/u/mostafa_a)\ **Post date:** [February 19, 2015, 7:36am UTC](https://www.ruby-forum.com/t/eye-diagram-error/234231/3 "2015-02-19T07:36:50Z")
Hi Marcus, I’m using GNURadio 3.7.5.1. Under [Graphical Sinks], I have “Baudline Sink” , “Fast AutoCorrelation Sink” and also “Eye diagram”. It doesn’t work! I didn’t get your hint of creating an eye diagram ☹ Best, Mostafa On Tue, Feb 17, 2015 at 9:39 PM, Marcus M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Marcus > **init** – * * * Department of Electrical Engineering Aboureyhan Building MMWCL LAB Amirkabir University Of Technology Tehran IRAN Tel: +98 (919) 158-7730 LAB: [http://ele.aut.ac.ir/~mmwcl/?page\_id=411](http://ele.aut.ac.ir/~mmwcl/?page_id=411) Homepage: [http://ele.aut.ac.ir/~alizadeh/](http://ele.aut.ac.ir/~alizadeh/) * * * ---
**Author:** ![mostafa\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/5e9695/32.png) [@mostafa\_a](https://www.ruby-forum.com/u/mostafa_a)\ **Post date:** [February 19, 2015, 10:34am UTC](https://www.ruby-forum.com/t/eye-diagram-error/234231/4 "2015-02-19T10:34:58Z")
Hi Mostafa, yep, these are not GNU Radio core visualizations, but come with gr-baz. You might be using a GNU Radio 3.6-compatible version of gr-baz instead of one that works with GR 3.7. Make sure to install the master branch of [GitHub - balint256/gr-baz: Collection of new blocks for GNU Radio](http://github.com/balint256/gr-baz) , after removing all remnants of the gr-baz version that you have. My hint regarding the eye diagram was just to build an eye diagram like it’s in the books [1]: An oscilloscope that is triggered on the symbol rate. Best regards, Marcus [1][Eye pattern - Wikipedia](http://en.wikipedia.org/wiki/Eye_pattern) ---
**Author:** ![mostafa\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/5e9695/32.png) [@mostafa\_a](https://www.ruby-forum.com/u/mostafa_a)\ **Post date:** [February 19, 2015, 9:37pm UTC](https://www.ruby-forum.com/t/eye-diagram-error/234231/5 "2015-02-19T21:37:45Z")
I’ll add one thing to Marcus’ recommendation: turn on persistence in the scope widget. Then you’ve got a great eye-diagram! Very Respectfully, Dan CaJacob On Thu, Feb 19, 2015 at 4:33 AM, Marcus Müller [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![mostafa\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/5e9695/32.png) [@mostafa\_a](https://www.ruby-forum.com/u/mostafa_a)\ **Post date:** [February 19, 2015, 9:42pm UTC](https://www.ruby-forum.com/t/eye-diagram-error/234231/6 "2015-02-19T21:42:17Z")
Dan, You can turn persistence on!? I use qt widgets, I don’t see that option in the Time Sink. Is this a WX only option? v/r, Rich ---
**Author:** ![mostafa\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/5e9695/32.png) [@mostafa\_a](https://www.ruby-forum.com/u/mostafa_a)\ **Post date:** [February 19, 2015, 9:56pm UTC](https://www.ruby-forum.com/t/eye-diagram-error/234231/7 "2015-02-19T21:56:43Z")
Sorry, that is a WX-only option for now. Sigh. Very Respectfully, Dan CaJacob On Thu, Feb 19, 2015 at 3:40 PM, Richard B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)