ETSI EN 301 927 V1.1.1 (2003-02)

SLOVENSKI STANDARD
SIST EN 301 927 V1.1.1:2006
01-februar-2006
Satelitske zemeljske postaje in sistemi (SES) – Evropsko sodelovanje pri
standardizaciji vesoljskih zadev (ECSS) - Satelitski vmesniki za obdelavo
programskih podatkov (SSDHI)
Satellite Earth Stations and Systems (SES); European Co-operation for Space
Standardization (ECSS); Satellite Software Data Handling Interfaces (SSDHI)
Ta slovenski standard je istoveten z: EN 301 927 Version 1.1.1
ICS:
33.060.30 Radiorelejni in fiksni satelitski Radio relay and fixed satellite
komunikacijski sistemi communications systems
SIST EN 301 927 V1.1.1:2006 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 301 927 V1.1.1:2006

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SIST EN 301 927 V1.1.1:2006

ETSI EN 301 927 V1.1.1 (2003-02)
European Standard (Telecommunications series)


Satellite Earth Stations and Systems (SES);
European Co-operation for Space Standardization (ECSS);
Satellite Software Data Handling Interfaces (SSDHI)

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SIST EN 301 927 V1.1.1:2006
 2 ETSI EN 301 927 V1.1.1 (2003-02)



Reference
DEN/SES-000-ECSS-2
Keywords
data, interface, LAYER 7, satellite, service
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SIST EN 301 927 V1.1.1:2006
 3 ETSI EN 301 927 V1.1.1 (2003-02)
Contents
Intellectual Property Rights.5
Foreword.5
Introduction .5
1 Scope.6
2 References.6
3 Definitions and abbreviations.6
3.1 Definitions.6
3.2 Abbreviations.8
4 Applicability.8
5 Recommendation guidelines.9
5.1 Objectives.9
5.2 Interface covering.9
5.3 Position of the standard proposed services with respect to other standards .10
6 Service specification.12
6.1 Introduction.12
6.2 Conventions.12
6.2.1 Service primitive naming.12
6.2.2 Parameter type and format abbreviations.13
6.3 Standard services.13
7 Services.16
7.1 Memory Management Service .16
7.2 Units power switching and resetting services.18
7.2.1 Device power switch-on service .18
7.2.2 Device power switch-off service .18
7.2.3 Device reset service .19
7.2.4 Device arming service .19
7.2.5 Function enabling service .20
7.3 Specific services.21
7.3.1 Platform Sensor and Actuator services .21
7.3.1.1 Specific sensors.21
7.3.1.1.1 Accelerometer service.21
7.3.1.1.2 Gyro service.22
7.3.1.1.3 Star tracker service .23
7.3.1.1.4 Earth sensor service.24
7.3.1.1.5 Sun Sensor service.26
7.3.1.1.6 Magnetometer service.26
7.3.1.2 Specific actuator.27
7.3.1.2.1 Thruster configuration service.27
7.3.1.2.2 Venting service.27
7.3.1.2.3 Apogee Boost Motor service .28
7.3.1.2.4 Thruster burst service .29
7.3.1.2.5 Plasmic Propulsion service.30
7.3.1.2.6 Wheel service.31
7.3.1.2.7 Pyrotechnic service.32
7.3.1.2.8 Magnetic-torquers service.34
7.3.1.3 Platform management.34
7.3.1.3.1 Battery reconditioning service.34
7.3.1.3.2 Power conditioning service .36
7.3.1.3.3 Stepper motor management service.37
7.3.2 Payload & TTC services .38
7.3.2.1 Synthesizers service.38
ETSI

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SIST EN 301 927 V1.1.1:2006
 4 ETSI EN 301 927 V1.1.1 (2003-02)
7.3.2.2 Power amplifiers service .39
7.3.2.3 Channel amplifier.40
7.3.2.4 Switching service.41
7.3.2.5 Digital Transparent Processor service.42
7.4 Simple devices services.45
7.4.1 Pulse command service.45
7.4.2 Temperature acquisition service.46
7.4.3 Pressure acquisition service .46
7.4.4 Current acquisition service .47
7.4.5 Voltage acquisition service.48
7.4.6 Frequency acquisition service.48
8 Design requirements.49
Annex A (informative): End to end example .50
Annex B (informative): Comments and recommendations for usage of the present document.51
B.1 Identifier type definition.51
B.2 Distinction between status and error parameters.51
B.3 Recommendations on services .52
B.4 SOIF services not kept in the present document .52
B.5 Services not defined in the present document .52
Annex C (informative): SOIF description.54
C.1 General.54
C.2 SOIF Command and Data Acquisition Service.55
C.3 Architectural Context.55
C.4 Service Operation - Service User Perspective.56
C.5 Service Operation - Service Providers Perspective.56
Annex D (informative): Parameter type code and format.57
D.1 Encoding formats of parameter types.57
D.2 Parameter type definitions.57
D.2.1 Boolean.57
D.2.2 Enumerated Parameter.57
D.2.3 Unsigned Integer.58
D.2.4 Signed Integer.58
D.2.5 Real.58
D.2.6 Bit-String.59
D.2.7 Octet-String.60
Annex E (informative): Bibliography .61
History .62

ETSI

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SIST EN 301 927 V1.1.1:2006
 5 ETSI EN 301 927 V1.1.1 (2003-02)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
All published ETSI deliverables shall include information which directs the reader to the above source of information.
Foreword
This European Standard (Telecommunications series) has been produced by ETSI Technical Committee Satellite Earth
Stations and Systems (SES).

National transposition dates
Date of adoption of this EN: 21 February 2003
Date of latest announcement of this EN (doa): 31 May 2003
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 30 November 2003
Date of withdrawal of any conflicting National Standard (dow): 30 November 2003

Introduction
Shorter and shorter communications satellites development cycles and compatibility requested with off the shelf
equipments requires interface standardization to be able to introduce a new equipment very late in satellite development
cycle. The present document will allow the development of On Board Software (OBSW) independently of the choice of
satellite equipment. It will be used to standardize the software specifications of the Interface between the application
software and the communication services. It shall help the standardization of equipment interface.
The present document addresses ISO OSI application layer services [1].
Currently, no application layer services standard exists for the Data System of geostationary communication satellites.
The aim of the present document is to respond to such requirements. Nevertheless, there are complementary agency
standards existing or in progress (see bibliography).
Integration or adaptation of new services, due to technology evolution, will be implemented through the maintenance of
the present document. The contents of the present document are subject to continuing work within TC-SES and may
change following formal TC-SES approval. Should TC-SES modify the contents of the present document it will then be
republished by ETSI with an identifying change of release date and an increase in version number as follows:
Version 1.m.n, where:
m The second digit (m) is incremented for all other types of changes, i.e. technical enhancements,
corrections, updates, etc.
n The third digit (n) is incremented when editorial only changes have been incorporated in the
specification.
ETSI

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SIST EN 301 927 V1.1.1:2006
 6 ETSI EN 301 927 V1.1.1 (2003-02)
1 Scope
The present document applies to Geostationary Communications Satellite architectures based on ISO OSI Reference
Model or SOIF Reference Model, but could also be applied to other types of satellites.
The present document sets out the minimum definition, services and interfaces requirements of the satellite
communication application layer.
The present document is complementary to Spacecraft Onboard Interfaces (SOIF).
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
[1] ISO/IEC 7498-1 (1994): "Information Technology - Open Systems Interconnection - Basic
Reference Model: The Basic Model".
[2] IEEE Standard 754-1985: "IEEE Standard for Binary Floating-Point Arithmetic".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Application Layer Service (ALS): entity which provides application software with a capability to operate devices,
with a warranty of performance
application software: on-board software implementing the satellite control functions
NOTE: A service is implemented by hardware and/or software. Application layer services for the control of
devices are defined in terms of:
the functions provided by the service;
a service access point;
the management parameters.
ETSI

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SIST EN 301 927 V1.1.1:2006
 7 ETSI EN 301 927 V1.1.1 (2003-02)
autonomy: ability of a system to provide without external intervention, mission services on a given period of time and
in a limited context: nominal or under anomaly conditions
NOTE: Three types of autonomy are defined:
reflex autonomy: characterizes the capability to perform predefined actions under triggering
events. This kind of autonomy, already in use, is performed through automation mechanisms, with
predefined sequences of states and triggering events (failure detection, isolation and recovery, etc.).
function autonomy: characterizes the capability of the satellite to perform automatic function on
board, implementing on board closed loops to maintain function performances without ground
intervention. Thermal regulation, batteries management, and attitude control are some examples of
function autonomy.
decision autonomy: characterizes the capability of the satellite to manage and update its schedule
of activities or tasks, taking into account events (expected or not) occurring during the mission
(Autonomous navigation, mission (re)scheduling, etc.).
Data Handling System (DHS): on-board system including computers and interface units hosting the application
software and providing communications between on-board units and with the ground
devices: devices are the onboard components that onboard application software control in order to perform the
operational objectives of the spacecraft
EXAMPLE: Sensors and actuators, Telemetry Command and Ranging (TCR) devices or other mission specific
devices.
st
J2000: earth centred co-ordinate reference system with an epoch of January 1 2000
primitive: a signal (e.g. a send request) which is passed across the service access point in order to use the service
capabilities
NOTE: The primitive may have associated parameters.
Service Access Point (SAP): the interface provided to a service through which users access the capabilities of the
service
NOTE: The service access points are defined in terms of a set of primitives.
spacelink interface: ground to satellite communication link for monitoring and control

Figure 1: Example of Spacecraft System
ETSI

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SIST EN 301 927 V1.1.1:2006
 8 ETSI EN 301 927 V1.1.1 (2003-02)
Service: Application Layer Service
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ABM Apogee Boost Motor
ACC ACCelerometer
ALSS Application Layer Services Standard
BSV Bi Stable Valve
CAMP Channel AMPlifier
DHS Data Handling System
DTP Digital Transparent Processor
EEPROM Electrically Erasable Programmable Read Only Memory
EPC Encapsulated Power Converter
ES Earth Sensor
EUC Engineering Unit Conversion
FDIR Failure Detection Isolation and Recovery
GYRO GYROscope
HW HardWare
ICD Interface Control Document
ISO International Standard Organization
MSV Mono Stable Valve
MT Magneto Torquer
OBSW On-Board SoftWare
OSI Open System Interconnection
PCU Power Conditioning Unit
PFC Parameter Format Code
PP Plasmic Propulsion
PTC Parameter Type Code
PUS Packet Utilization Standard
PYRO PYROtechnic
RAM Random Access Memory
ROM Read Only Memory
RW Reaction Wheel
SAP Service Access Point
SDB System Data Base
SM Stepper Motor
SOIF Spacecraft Onboard InterFaces
SS Sun Sensor
SSDHI Satellite Software Data Handling Interfaces
STR Star TRacker
SW SoftWare
TC Tele Command
TCR Telemetry, Command and Ranging
TOM Thruster Orientation Mechanism
TWTA Travelling Wave Tube Amplifier
4 Applicability
The present document can be applied to all classes of spacecraft including in particular communications satellites.
ETSI

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SIST EN 301 927 V1.1.1:2006
 9 ETSI EN 301 927 V1.1.1 (2003-02)
5 Recommendation guidelines
5.1 Objectives
The main recommendation drivers are:
• Development optimization:
- Standardization data format.
- Using common formats for key commands across different data buses.
- Planning optimization by minimising development time.
- Cost by reducing engineering process on specification and development of application layer services.
- Minimising risk basing the development on validated requirements.
- Increasing potential for flight equipment, software (SW) and test equipment reuse.
- Overlapping of software development with hardware development:
It will be possible to optimize this process by applying the present document which provides
requirements independent of any hardware configuration.
This concept allows to freeze application layer Interface Control Document (ICD) to guarantee
hardware independence.
• Performance constraints:
- Real time.
- Memory size.
- Load of onboard communication data bus.
- Device Observability.
- Device Commandability.
- Number and type of units to interface.
- Operations complexity.
5.2 Interface covering
Data communication on satellite requires electrical and data interfaces onboard. These interfaces include:
• Hardware interfaces:
- Electrical interfaces (power, command, acquisition, pyrotechnic, etc.) to devices.
- Onboard communication data buses.
• Software interfaces:
- Software drivers controlling devices and communication on data buses.
- Application software interfaces.
The application layer is the highest layer of the reference OSI [1] and SOIF (see bibliography) models (see figure 2). In
the OSI Reference Model, the application software is not included in the reference model application layer, since this
software is the user of the communications services provided by the OSI Reference Model.
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SIST EN 301 927 V1.1.1:2006
 10 ETSI EN 301 927 V1.1.1 (2003-02)
The present document provides recommendations to interface application services between themselves and to other
OSI/SOIF layers. In particular, it defines the services to interface devices with application software independent of
lower layer levels (particularly the electrical interface).

OSI mapping SOIF mapping
Application layer
Application layer
Presentation layer
Session layer
Transport layer
Transport layer
Network layer Network layer
Data link layer
Data link and physical
layer
Physical layer

Figure 2: OSI and SOIF layers mapping
5.3 Position of the standard proposed services with respect to
other standards
The present document implies the provision of certain underlying services, that could be provided by SOIF
(see annex C):
• Command and Data Acquisition service;
• Time service;
• File transfer service.
The present document does not address in particular:
• Task management;
• On-board scheduling;
• Satellite System FDIR.
User Application Layer definition:
This layer contains satellite application services like AOCS management, Control and Data management and FDIR
management, unit management, etc. This layer shall be independent of the underneath layers in term of equipment
manufacturer and transmission protocol/media. The goal is to provide user application reuse capability.
User application services implementation can call (see figure 3):
• Other user application layer services;
• Application Interface services;
• SOIF or non SOIF application layer services (see annex C);
• Any other lower layer services with exposed Service Access Point.
ETSI

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SIST EN 301 927 V1.1.1:2006
 11 ETSI EN 301 927 V1.1.1 (2003-02)
Application Interface Services definition:
These services provide satellite function or equipment oriented services with an interface independent of the equipment
manufacturer or of the transmission protocol/physical link.
The service implementation requires the equipment database in order to make the link between the standardized
interface and the equipment function.
Although the service implementation is equipment dependent, the objective is to use common services provided by
e.g. the SOIF
...