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9 OBDH Technology of Lunar Lander
Fig. 9.2 Architecture diagram of Chang’E-3 OBDH subsystem
multiplexing and storage, driving of heating loops controller and mechanism control.
SMU should receive data from the commands sent by ground stations, control the
operation of serial data bus and lower computer, provide onboard time reference,
collect all kinds of telemetry data and format downlink telemetry frame, and provide
multiple data multiplexing, large capacity storage and etc.
Data Interface Unit (DIU) was an intelligent terminal based on a single chip microcomputer. It directly served the users in –Y module. DIU received commands from
SMU and sent telemetry data to SMU through the serial data bus. DIU performed
the power distribution of –Y module, the acquisition of telemetry data and the distribution of indirect commands, as well as the control and driving of heating loops and
mechanisms.
The Serial Data Bus (SDB) was the channel for data transmission among SMU,
DIU, GNC computer, payloads and other terminals.