TCTM - Model Driven TC/TM Protocol Design
Communication with satellites is based on a so-called telecommand (TC)/telemetry (TM) interface. This interface is also maintained on the satellite platform to interconnect its instruments with the central on-board computer.
Although this kind of interface is standardized, the definition leaves certain freedom for mission-specific implementations. In the design of satellite instruments the NRE (non-recurring engineering) effort required to adapt the TC/TM interface to the actual needs of the mission is significant as modifications affect not only the flight software but also the documentation, the Satellite Reference Database (SRDB) and the test software.
The following design tasks were performed within the framework of the project:
- The database itself was defined on an XML basis including all generic definitions for TC/TM protocols.
- The API (Application Programming Interface) was established supporting functions to extract, add, delete and modify database items. This API was written in C++ and provides extensive consistency checks on the database.
- A GUI (Graphical User Interface) was developed to define TCTM entries (TCTM DefEditor). This editor is also based on the API and uses the Qt library for the graphical functions.
The work performed was subjected to practical testing within the framework of a new TC/TM interface for an upcoming satellite mission. The complete TC/TM structure for the mission was established via the TCTM DefEditor and subsequently used by the TEM SW (Test Equipment Manager Software).
RUAG Space GmbH - Heinrich Fragner