--- date: 2025-11-23 --- # Universal Robots real-time data exchange (RTDE) using C# :::{card} Background A colleague and me wanted to find a C# library for controlling a [Universal Robots UR3 robot arm](https://www.universal-robots.com/products/ur3-robot/) with an [OnRobot RG2 gripper](https://onrobot.com/en/products/rg2-gripper) for using in an [industrial programming-related course](https://kurser.dtu.dk/course/62236). ::: At the end I saw that it requires about a dozen C# lines to activate the robot and send the robot program. I reverse engineered the URScript RPC commands by storing an example URScript created by the UR operating system on a USB stick. In the first iteration of the course we had bought the UniversalRobots.NET library. ## Related links Here is an overview of resources I researched: - : A high-quality open-source C++ library from SDU with Python bindings. It can automatically load the control script for the robot and even restart it after a safety lock. - : A low-quality Python library, but it is the only one that I could find that can interface with the UR robot. It can get the gripper width and apply width along with force. - : An undocumented C# library, which lacks functions like automatic loading of control script and inverse kinematics for controlling the gripper in base coordinates. - : Python library for some OnRobot grippers. Can only interface the control box of the gripper directly. - [RoboDK](https://robodk.com): Commercial simulator and programmer with support for most industrial robot arms. Features a [C# API](https://robodk.com/doc/en/RoboDK-API-API.html). This solution is non-free and probably abstract *too* much for a C# programming course. - [UniversalRobots](https://github.com/underautomation/UniversalRobots.NET): A high-quality commercial C# library for RTDE that must be licensed. They provide an academic license with ~40% off at 594 EUR. According to UnderAutomation it is a perpetual license independent of how many students or robots.