This thesis describes the provision of the data communication of the new protection relays via 6 kV switch gears to the electro monitoring system at the Dukovany Nuclear Power Station. These protection relays will replace the current analog protection. The replacement process will start in 2015 and will finish in 2018. Given the overall complexity of the project, this thesis deals only with the following 6 kV switch gears 9BB and 9BD. The thesis is divided into a theoretical and a practical part. The theoretical part concerns the actual consumption and output of the Dukovany Nuclear Power Station. The following chapters describe the electro monitoring system and GRAF and LOGA software programs that are closely connected with it and that were used in the practical part. The last chapter of the theoretical part deals with the actual replacement of the protection relays of the 6 kV switch gears. Also, it describes a new optical network, which will be set up at the Dukovany Nuclear Power Station as a part of the process of replacement. The segment of the practical part concerns laboratory verification of the data communication of the new protection relays. Next, it describes actions that had to be taken in order to ensure and verify correct functionality of the data communication. This part is followed up by a closely related practical activity, which describes examination and verification of the protection functions of each of the 9BB and 9BD switch gears protection relays.