It is designed to be highly portable so that it is easy to use for building into different software systems, such as spacecraft simulators and on-board telecommand decoders. It gives access through an API (Application Programming Interface) to the telecommand facilities using calls in ANSI-C.
The Telecommand Decoder Shell accepts the incoming telecommand data. The data can be supplied as Communications Link Transmission Units (CLTUs) each containing a telecommand transfer frame, or as the candidate BCH codeblocks of a CLTU. The Shell delivers packets and the other SDUs (service data units) defined for the TC Space Data Link Protocol. It also delivers Communications Link Control Words (CLCWs) for the spacecraft telemetry.
The Shell also provides support for ESA Telecommand Authentication as an optional extra. When this option is selected, the Shell validates the authentication tail of telecommand segments.
The facilities and interfaces of the Telecommand Decoder Shell package are described further in the detailed description.
The Telecommand Decoder Shell package has a unique feature: Built-In-Failures (BIFs). The BIFs can be switched on and off as required for testing the behaviour of elements of the spacecraft ground system in exception situations. This capability for controlled generation of spacecraft errors is an advantage of our software-based telecommand decoder.
The Telecommand Decoder Shell package is also ideal for building demonstration
systems. To demonstrate ground system telecommand elements to users or customers,
there is no need for spacecraft hardware.
The Telecommand Decoder Shell can be used to build a software-based simulation
of the spacecraft behaviour.
Please contact us for further information on technical questions or licensing conditions for the Telecommand Decoder Shell package.
Detailed Description
TC Features
Operational Applications