# XCOS issue "value must be between 1 and 98"

**URL:** <https://scilab.discourse.group/t/xcos-issue-value-must-be-between-1-and-98/245>\
**Category:** Xcos\
**Created:** [November 18, 2023, 4:54pm UTC](https://scilab.discourse.group/t/xcos-issue-value-must-be-between-1-and-98/245 "2023-11-18T16:54:23Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![misterwhy](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@misterwhy](https://scilab.discourse.group/u/misterwhy)\
**Post date:** [November 18, 2023, 4:54pm UTC](https://scilab.discourse.group/t/xcos-issue-value-must-be-between-1-and-98/245/1 "2023-11-18T16:54:23Z")

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Hello everyone,

I’m making a PID controler with XCOS, but I got an error that I can’t explain (I’m newbee).

Please look at my error message :

 ![WhatsApp Image 2023-11-18 at 17.49.41](https://global.discourse-cdn.com/free1/uploads/utc/original/1X/12dbe26096a26db02683e8d3a5b17b54479c9d4d.jpeg)

Here’s my code: [acc\_angulaire\_save\_2.zcos](https://scilab.discourse.group/uploads/short-url/t55QDAEEDHom2P8XSRASMfGTUHK.zcos) (27.1 KB)

Thank you very much to help me figure it out.

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<div class="post-metadata">

**Author:** ![mottelet](https://yyz2.discourse-cdn.com/free1/user_avatar/scilab.discourse.group/mottelet/32/13_2.png) [@mottelet](https://scilab.discourse.group/u/mottelet)\
**Post date:** [November 20, 2023, 7:58am UTC](https://scilab.discourse.group/t/xcos-issue-value-must-be-between-1-and-98/245/2 "2023-11-20T07:58:51Z")

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Hello,

Your diagram is very complex, are you really a Xcos newbie ? When running the simulation there are also a lot of warnings because you have chosen to run the diagram in trace/debug mode. I think the basic problem comes from the solver non-convergence. By taking larger RTOL and ATOL (try 1e-2 for both) you will see that some instability occurs as at least 2 of the outputs seem to become unbounded. So, the problem is likely due to the conception of some component of you diagram which causes the instability and not due to Xcos itself.

S.

 ![Capture d’écran 2023-11-20 à 09.40.40](https://global.discourse-cdn.com/free1/uploads/utc/original/1X/9e863c0b820321a2947502dfffebeb68416dce3a.png)  
 ![Capture d’écran 2023-11-20 à 09.39.06](https://global.discourse-cdn.com/free1/uploads/utc/original/1X/3fd67546903222ca23911012b0aaef799fb1a0e8.png)  
 ![Capture d’écran 2023-11-20 à 09.39.10](https://global.discourse-cdn.com/free1/uploads/utc/original/1X/608c5dd427990417712df329128f09274c531971.png)