For operation and monitoring, the SOFIA telescope assembly comprises a dedicated controls system. Basically this system appears to the user to consist of four major controller subsystems: Master Control Processor (MCP), Tracker Controller (TRC), Telescope Assembly Servo Control Unit (TASCU) and Secondary Mirror Controller (SMC). They are accessible via a single command driven interface link through the MCP. With the example of the subsystems MCP and TRC, commonality aspects in communication interface architecture and software protocol selection are discussed. The special requirements associated with the installation in an aircraft are considered as well as maintenance aspects for 20 years of operation. The paper covers user relevant hard-/software design aspects of the TA flight as well as ground support systems. The usage of the TA data structure definitions, provided in XML, throughout the whole observatory for interface description and implementation are explained.