A medical system comprising: a medical device including a first display device, a first wireless communication circuit configured to transmit wireless signals and to receive wireless and remotely generated signals, a first processor including a first memory having instructions stored therein that are executable by the first processor to generate screen data for display on the first display device, to transmit the screen data via the wireless communication circuit, and to control the first display device to display a predefined screen that is different from the screen data, and a remote electronic device including a second display device, a second wireless communication circuit configured to transmit wireless signals and to receive wireless and remotely generated signals, and a second processor including a second memory having instructions stored therein that are executable by the second processor to receive screen data from the medical device via the second wireless communication circuit and to control the second display device to display the screen data generated by the first processor of the medical device, characterised in that the medical device is configured to be remotely controlled in an remote terminal operating mode, the remote electronic device is configured to remotely control the medical device in the remote terminal operating mode, the second memory of the second processor of the remote electronic device has instructions stored therein that are executable by the second processor to reset an alive timer each time the second processor transmits a message via the second wireless communication circuit and to transmit an alive message via the second wireless communication circuit if the alive timer times out between transmission of messages via the second wireless communication circuit, and the first memory of the first processor of the medical device has instructions stored therein that are executable by the first processor to reset an alive message timer each time the first processor receives via the first wireless communication circuit a message transmitted by the second processor via the second wireless communication circuit, and to exit the remote terminal operating mode if the alive message timer times out between receiving via the first wireless communication circuit messages transmitted by the second processor via the second wireless communication circuit. a medical device including a first display device, a first wireless communication circuit configured to transmit wireless signals and to receive wireless and remotely generated signals, a first processor including a first memory having instructions stored therein that are executable by the first processor to generate screen data for display on the first display device, to transmit the screen data via the wireless communication circuit, and to control the first display device to display a predefined screen that is different from the screen data, and a remote electronic device including a second display device, a second wireless communication circuit configured to transmit wireless signals and to receive wireless and remotely generated signals, and a second processor including a second memory having instructions stored therein that are executable by the second processor to receive screen data from the medical device via the second wireless communication circuit and to control the second display device to display the screen data generated by the first processor of the medical device, characterised in that the medical device is configured to be remotely controlled in an remote terminal operating mode, the remote electronic device is configured to remotely control the medical device in the remote terminal operating mode, the second memory of the second processor of the remote electronic device has instructions stored therein that are executable by the second processor to reset an alive timer each time the second processor transmits a message via the second wireless communication circuit and to transmit an alive message via the second wireless communication circuit if the alive timer times out between transmission of messages via the second wireless communication circuit, and the first memory of the first processor of the medical device has instructions stored therein that are executable by the first processor to reset an alive message timer each time the first processor receives via the first wireless communication circuit a message transmitted by the second processor via the second wireless communication circuit, and to exit the remote terminal operating mode if the alive message timer times out between receiving via the first wireless communication circuit messages transmitted by the second processor via the second wireless communication circuit.