Packetised telemetry and telecommand on ESA spacecraft

ESA packetised telecommand and telemetry standards are closely related to the `Blue Book´ recommendations of the international Consultative Committee for Space Data Systems. Packetisation will permit highly automated data routing between on-board sources and users and substantially eliminate the need for spacecraft-specific hardware and/or software at intermediate points within the data distribution networks. An interface was proposed to meet the telemetry and telecommand requirements of scientific instruments included in the model payloads of the ESA Cluster and SOHO spacecraft. This interface known as the Packetised Serial Interface or PSI, is described