Service Module data handling
The data handling architecture is decentralised because the Payload Module (PLM) and Service Module (SVM) have their own computer.
Standard On-Board Data Handling (OBDH) data buses are used for data exchanges between the Service Module (SVM) and Payload Module (PLM) computers and the remote unit. The bus couplers are used in several SVM units to interface with the OBDH bus.
The SVM data management is done by the Central Communication Unit (CCU), including a MA 31750 microprocessor with two redundant memory modules of 224 Kwords. The CCU performs the data exchange with the OBDH bus, bus couplers and on-board time generation and synchronisation. The decoding and reconfiguration unit (EDR) interfaces with the S-band transponder. It carries out:
- telecommand receipt
- execution of Command Pulse Direct Unit (CPDU) telecommands
- CCU supervision
The housekeeping and pyrotechnics unit (BSP) is in charge of:
- the generation of pyrotechnics commands
- temperature measurements and
- actuation of heaters for the SVM
- housekeeping of some SVM units
The Electrical Interface Unit (EIU) is responsible for the:
- release and deployment of the solar array
- telemetry/telecommands (TM/TC) for some parts of the SVM
