Abstract: A method and apparatus for designating a particular model vehicle for a command function without punching in the ID of the model vehicle. A remote control device is positioned near one of the model vehicles. A limited field transmission occurs between the model vehicle and the remote control device. The device may be a train engine transmitting its train ID periodically via an infrared (IR) transmission. The remote near the train automatically receives the IR transmission of the train ID, so that the next press of a command button will automatically go to that train ID without needing to punch in the ID number.

Abstract: Expanding the capacity of a fixed digital field using a unique number calculated from the digital field, such as an error code. Expansion is possible by calculating a new error code using a different algorithm. A recipient, upon not detecting the error code from the original algorithm, checks for the new error code before indicating an error. The presence of the new error code acts like an extra bit to give an entirely new set of numbers for the digital field, thus doubling the command set. In another aspect of the invention, fill bits between transmission packets are used to indicate further data, and are included in calculating the new error code.