ISO 20217:2015 pdf download.Recommendation for Space Data System Practices
1.1 PURPOSE AND SCOPE OF THIS DOCUMENT
This document defines the Spacecraft Onboard Interface Services (SOIS) File and Packet Store Services (FPSS). The definition encompasses specification of the service interface exposed to onboard software (user applications and libraries) as well as the conceptual mapping of the FPSS primitives to the protocols implementing such services.
The SOIS File and Packet Store Services are for use by onboard software to:
– Access, and manage files residing in a file store. The files residing in the file store could contain any type of data, including for example telemetry, commands and command sequences, software updates, imagery, and other science observations.
– Access and manage packets residing in a packet store. It should be noted that the packet store may or may not be aware of, and its actions may or may not be informed by, the contents of a packet.
To achieve this, the FPSS comprise the following services:
– File Access Service (FAS);
– File Management Service (FMS);
– Packet Store Access Service (PSAS);
– Packet Store Management Service (PSMS).
It should be noted that the SOIS File and Packet Store Services do NOT define the file and packet stores themselves, but only their minimum provided service. The initialization and configuration of the file and packet stores is out of scope for this document.
1.2 APPLICABILITY
This document applies to any mission or equipment claiming to provide CCSDS SOIS-compatible File and Packet Store Services.
1.3 RATIONALE
SOIS provides service interface specifications in order to promote commonality of functionality amongst systems implementing well-defined services. These interfaces do not dictate implementation of interfaces or protocols supporting the services.
1.4 DOCUMENT STRUCTURE
This document has four major sections:
– section 1, this section, containing administrative information, definitions, and references;
– section 2, containing the general concepts and assumptions;
– section 3, containing the File and Packet Store Services, in terms of the services provided, services expected from underlying layers, and the service interface;
– section 4, containing the Management Information Base (MIB) for this service.
In addition, one normative and four informative annexes are provided:
– annex A, comprising a Service Conformance Statement Proforma;
– annex B, containing a discussion security considerations with respect to the specifications of this document;
– annex C, containing a list of acronyms;
– annex D, containing a list of informative references;
– annex E, describing aspects of the POSIX API file functions which might be useful to implementers of the File Access and Management Services.