This paper presents a comprehensive study on the implementation of real-time digital twins for industrial cobots, with a focus on the ABB GoFa CRB 15000 cobot. It highlights the relevance of digital twins in the context of Industry 4.0 and their ability to improve operational efficiency by representing physical processes in virtual models. The project's primary objective is to develop a real-time digital twin system to develop the bidirectional monitoring and control of industrial cobots, particularly in assembly tasks. This paper addresses the challenges encountered and the proposed solution, which include offline and online programming, the adoption of the OPC UA protocol for communication, and the use of ABB RobotStudio for simulation. A framework for understanding the implementation is provided, followed by a detailed analysis of the results obtained, as well as discussion and conclusions. An exploration of possible future work is also included, providing a comprehensive view of the project and its importance in the field of industrial robotics and digital twin technology.