The data handling system is the central component onboard a satellite responsible for interpretation and distribution of telecommands received from ground and collection of telemetry subsequently sent to ground.
Context Diagram

     SmartDraw Drawing

For the OBOSS-III product, the context of the data handling system is perceived as shown above.

The Data Handling System Interfaces to the ground control center through a Communications (COM) subsystem.

At the other side, a range of onboard subsystems are situated on an onboard bus. All telecommands to these and telemetry from these go through the data handling system.

The top-level architectural design is presented in the OBOSS-III Design Specification.

The following documents define the requirements to be fulfilled by the OBOSS-III product as well as the reuse process applicable to it.

OBOSS-III Software Requirements Specification: Software requirements applicable to the reusable OBOSS-III components.
OBOSS-III Manual for Reuse: Guidance to the adaptation process in which a mission specific data handling software system is produced based on the OBOSS-III product.
OBOSS-III Operations Manual: Description of packet utilization services supported by OBOSS-III