A system for use in a production environment, the system being configured to control an apparatus, according to user input, comprising: a server coupled to the apparatus by a computer network , the server having a database that includes the present values for one or more operating parameter values indicating a current operating status of the apparatus; a wireless transmitter associated with or coupled to the apparatus, the transmitter configured to automatically transmit data packets wirelessly, wherein the data packets include a reference value representing the signal strength of the transmitter at a predetermined distance and an identifier identifying the apparatus; and a portable computer wirelessly coupled to the computer network, the computer including a processor and an input device, a display device, and a receiver coupled to the processor; wherein the portable computer is configured to automatically receive the data packets from the transmitter via the receiver , wherein the receiver is configured to measure the received strength of signals sent by the transmitter , and wherein the portable computer is configured to compare the reference value in the data packets and the received signal strength from the receiver to determine a current distance between the transmitter and the portable computer ; wherein the portable computer is configured to display a user interface, and to switch the user interface to an apparatus specific user interface that includes the one or more operational parameter values for the apparatus identified by the identifier in the data packets received by the portable computer from the wireless transmitter when the computer crosses a predetermined threshold distance from the transmitter; and wherein the portable computer's input device is configured to accept input from the user and to send the input to the apparatus. a server coupled to the apparatus by a computer network , the server having a database that includes the present values for one or more operating parameter values indicating a current operating status of the apparatus; a wireless transmitter associated with or coupled to the apparatus, the transmitter configured to automatically transmit data packets wirelessly, wherein the data packets include a reference value representing the signal strength of the transmitter at a predetermined distance and an identifier identifying the apparatus; and a portable computer wirelessly coupled to the computer network, the computer including a processor and an input device, a display device, and a receiver coupled to the processor; wherein the portable computer is configured to automatically receive the data packets from the transmitter via the receiver , wherein the receiver is configured to measure the received strength of signals sent by the transmitter , and wherein the portable computer is configured to compare the reference value in the data packets and the received signal strength from the receiver to determine a current distance between the transmitter and the portable computer ; wherein the portable computer is configured to display a user interface, and to switch the user interface to an apparatus specific user interface that includes the one or more operational parameter values for the apparatus identified by the identifier in the data packets received by the portable computer from the wireless transmitter when the computer crosses a predetermined threshold distance from the transmitter; and wherein the portable computer's input device is configured to accept input from the user and to send the input to the apparatus. <EOS>