# C0040401 error: no connection with controller **URL:** \ **Category:** RobotStudio\ **Created:** [March 28, 2014, 8:24am UTC](https://tech-community.robotics.abb.com/t/c0040401-error-no-connection-with-controller/6047 "2014-03-28T08:24:51Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![pjxia](https://avatars.discourse-cdn.com/v4/letter/p/a5b964/32.png) [@pjxia](https://tech-community.robotics.abb.com/u/pjxia)\ **Post date:** [March 28, 2014, 8:24am UTC](https://tech-community.robotics.abb.com/t/c0040401-error-no-connection-with-controller/6047/1 "2014-03-28T08:24:51Z")
Sorry, guys, I am new to ABB robotstudio. I want to use ABB IRB140 for welding. Currently I try to study RAPID programming. I have input all my models, including robot, tool and work piece, and then planned a short path, in the simulate module I synchronized the path to the VC already, then I can simulate the robot path, no problem. And now, I want to test the RAPID programming. In the controller and RAPID module, I can see the generated RAPID code, and then if I want to change the RAPID code, and start execution of the RAPID code, there is C0040401 error: no connection with controller. However, even if I do not change any RAPID code, the same error. How to fix this problem? Is there any examples to start RAPID programming? Thanks Best regards ---
**Author:** ![pjx](https://avatars.discourse-cdn.com/v4/letter/p/7feea3/32.png) [@pjx](https://tech-community.robotics.abb.com/u/pjx)\ **Post date:** [April 9, 2014, 8:07am UTC](https://tech-community.robotics.abb.com/t/c0040401-error-no-connection-with-controller/6047/2 "2014-04-09T08:07:19Z")
No answer? Nobody has this problem? ---
**Author:** ![pjx](https://avatars.discourse-cdn.com/v4/letter/p/7feea3/32.png) [@pjx](https://tech-community.robotics.abb.com/u/pjx)\ **Post date:** [April 9, 2014, 8:07am UTC](https://tech-community.robotics.abb.com/t/c0040401-error-no-connection-with-controller/6047/3 "2014-04-09T08:07:19Z")
No reply? Nobody has this problem?