# C-API on Robot Controller

**URL:** <https://forum.universal-robots.com/t/c-api-on-robot-controller/2808>\
**Category:** URScript\
**Created:** [September 26, 2018, 1:21am UTC](https://forum.universal-robots.com/t/c-api-on-robot-controller/2808 "2018-09-26T01:21:27Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![anon61517813](https://avatars.discourse-cdn.com/v4/letter/a/a9adbd/32.png) [@anon61517813](https://forum.universal-robots.com/u/anon61517813)\
**Post date:** [September 26, 2018, 1:21am UTC](https://forum.universal-robots.com/t/c-api-on-robot-controller/2808/1 "2018-09-26T01:21:27Z")

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Good day everyone.  
Is it still possible to make customized C program for the UR controller?

Before, there were 3 ways of controlling the robot.  
1. GUI (Polyscope)  
2. UR Script  
3. C-API

Starting from version SW3.3…UR removed C-API.  
And it’s hard to find a reference/information about it now.  
Any help would be greatly appreciated. 🙂

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**Author:** ![ajp](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.universal-robots.com/ajp/32/471_2.png) [@ajp](https://forum.universal-robots.com/u/ajp)\
**Post date:** [October 1, 2018, 8:46am UTC](https://forum.universal-robots.com/t/c-api-on-robot-controller/2808/2 "2018-10-01T08:46:17Z")

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Hi @anon61517813,

You’re right that it’s no longer supported, but a lot of the same functionality can be achieved using the RTDE interface. What is it that you’re looking to do?

[https://www.universal-robots.com/how-tos-and-faqs/how-to/ur-how-tos/real-time-data-exchange-rtde-guide-22229/](https://www.universal-robots.com/how-tos-and-faqs/how-to/ur-how-tos/real-time-data-exchange-rtde-guide-22229/)

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**Author:** ![anon44541449](https://avatars.discourse-cdn.com/v4/letter/a/278dde/32.png) [@anon44541449](https://forum.universal-robots.com/u/anon44541449)\
**Post date:** [June 8, 2021, 11:08am UTC](https://forum.universal-robots.com/t/c-api-on-robot-controller/2808/3 "2021-06-08T11:08:55Z")

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Hi,

we have a CB2 UR10 (actually two of them mounted on a pi4 workerbot from before 2015) for a research project that involves dynamic motions, for which being able use the C-API would probably help a lot, since we can’t use any of the newer interfaces such as RTDE. We are currently using a modified version of the ur\_modern\_driver (outside a ROS context) which has some limitations and we would like to run parts of the software directly on the control box.

Is there any possibility to still get the C-API from somewhere even though it is not supported by current hardware? The only link I found is dead ([http://ur-update.dk/URsupport/Software/C-API/](http://ur-update.dk/URsupport/Software/C-API/) on [ur\_c\_api\_bringup - ROS Wiki](http://wiki.ros.org/ur_c_api_bringup)).