A control system of an elevator can be communicated with by a mobile control device to execute a maintenance and/or installation for the elevator. The control system includes a receiving element for receiving a request to establish a communication connection from the mobile control device, at least one processor to perform a first identification whether the mobile control device is authorized to communicate with the elevator, the at least one processor to perform a second identification whether a user of the mobile control device is authorized for using this mobile control device and/or for servicing this elevator, the at least one processor for matching a right of access of the mobile control device to the elevator depending on results of the first and the second identification, and a communication element to establish the requested communication connection according the matched right of access of the mobile control device.