The design of LBT's telemetry source registration

In the current report, we describe the structure of the telemetry logging system of the Large Binocular Telescope (LBT) and its approach to telemeter registration. The telemetry logging system, called Telemetry, has three functions. It will provide system data to LBT Observatory (LBTO) personnel in order to facilitate engineering activities such as commissioning, failure diagnosis and system repair. In order to detect failures as soon as possible after they occur, telemetry will allow for live monitoring of the functional status of key telescope systems. Finally, in order to help personnel understand how the LBT operating characteristics evolve with time, telemetry will provide access to historical telescope system data. Given this range of functions, a key requirement of Telemetry is that it must easily adapt to new sources of data. To minimize the changes required to Telemetry, it has no pre-existing knowledge about the structure of the data it will collect. Instead, it engages in a telemeter registration process, in which the data source must describe its own structure. This registration process requires no external data files to be maintained since the description is built up by a sequence of function calls to a C++ library. So far, this strategy has proven successful, as only minor modifications have been made to accommodate the nearly 400 sources of data introduced to the system in the past year. The current report describes the design of the LBT telemetry system and its source registration process.