Abstract: There is provided an isolator module for use in a surgical robotic system which comprises a robot arm and a controller. The isolator module is configured to provide an interface between the robot arm and the controller of the surgical robotic system. The isolator module comprises a first interfacing portion configured to: (i) transfer power to a first cable that is connected to the robot arm, and (ii) transfer data to and from the first cable, and a second interfacing portion configured to: (i) transfer power to a second cable that is connected to the controller, and (ii) transfer data to and from the second cable. The isolator module further comprises a data link connecting the first interfacing portion to the second interfacing portion, the data link being configured to transfer data in both directions between the first interfacing portion and the second interfacing portion whilst providing electrical isolation between the first interfacing portion and the second interfacing portion.