ABSTRACT
The system's command component has become more important over the years because payloads are not necessarily passive devices. The user interface provides the means to translate between ways of encoding the command data so that both the user and the payload understand the instructions. Additionally, the telemetry stream becomes a feedback loop to the operators to indicate whether the payload has received the commands properly. Certain system characteristics distinguish the telecommand process from the simple links between a computer and its peripheral devices. This chapter discusses command composition and command strategies for actual transmission over a radio link, the problems encountered in transmitting commands, and the impacts of commanding that leads to corruption by the links. It examines three command transmission strategies that the designer can use for a variety of payload classes. The three basic philosophies are repeat and execute; command, verify, and then execute and execute immediately.
