Transcript Example of EDS usage in SOIS - Home

Example of EDS usage in SOIS
F. Torelli
ESTEC
23/06/2011
ESA UNCLASSIFIED – For Official Use
Introduction
1. Objective:
– To give an example of how SOIS C&DA services and EDS can
map to Star Tracker TM/TC ICD.
2. Inputs:
– STR_TM_TC_packets_V4.xls
– Report from CCSDS SOIS Spring Meeting 2011
– Notes from CCSDS SOIS Fall Meeting 2010
3. Entities involved:
– Common Data Dictionary (CDD)
– Electronic Data Sheet (EDS)
– Device Access Service (DAS)
– Device Virtualisation Service (DVS)
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 2
ESA UNCLASSIFIED – For Official Use
SOIS PnP Architecture
Applications
Contains the ICD of the
devices w.r.t. the SOIS
service interfaces.
Device Virtualisation
Service
CDD
EDS
Device Enumeration
Service
Device Access
Service
Standardised interface
including semantics.
Ref. sheet 1 in
STR_TM_TC_packets_V4.
Device specific functional
interface.
Ref. sheet 2, 3, 4 in
STR_TM_TC_packets_V4.
SOIS
Contains syntactic and
semantic types.
Policy
Subnetwork
Management and
Configuration
Subnetwork
Device Discovery
Service
Subnetwork
Packet or Memory
Access Service
Subnetwork
Plug-and-Play
Protocol
Subnetwork
Protocol
Implementations
Hardware
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 3
ESA UNCLASSIFIED – For Official Use
Subnetwork
Implementation
Common Data Dictionary & Electronic
Data Sheet
–
The CDD contains the attributes to be used to describe the device
and in particular its interfaces (i.e. syntactic and semantic types).
–
The CDD is the vocabulary used to build the EDS for a particular
device.
–
The elements of the CDD arranged (and instantiated) in the EDS for
a specific device allow to associate a meaning to the raw data in the
“TM and TC” of that device.
–
The EDS describes the mapping between the layers in the SOIS
Command & Data Acquisition (C&DA) in terms of service primitives
and their parameters.
–
The EDS describes the mechanisms to send/receive data to/from the
devices and how to elaborate them along the C&DA stack.
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 4
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Example of CDD (1/2)
The provided types are examples
used along the presentation for
practical reasons, but are not the
finalised elements of the SOIS CDD.
Basic Syntactic Types:
Type Identified
Max Range
Comment
Real (single precision) Type
[-inf, inf]
Ranges of specific attributes can be smaller
Real (double precision) Type
[-inf, inf]
Ranges of specific attributes can be smaller
Integer (32bits) Type
[-231, 231-1]
Ranges of specific attributes can be smaller
Natural (32bits) Type
[0, 232-1]
Ranges of specific attributes can be smaller
Natural (16bits) Type
[0, 216-1]
Ranges of specific attributes can be smaller
Time (64bits) Type
[(0, 0), (232-1, 1-2-24)]
CUC format (s, sub-s)
Composite Syntactic Types:
Type Identifier
Structure
Range
Quaternion Type
Array of 4 Real(double)
[-1, 1]
Real Vector Type
Array of 3 Real(double)
[-inf, inf]
Ranges of specific attributes can
be smaller
Integer Vector Type
Array of 3 Integer(32bits)
[-231, 231-1]
Ranges of specific attributes can
be smaller
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 5
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Comment
Example of CDD (2/2)
The provided types are examples
used along the presentation for
practical reasons, but are not the
finalised elements of the SOIS CDD.
Semantic Types:
Type Identifier
Syntactic Type
Unit
Comment
Final Attitude
Quaternion Type
-
Reference frame: J2000 frame --> sensor frame
Final Attitude
Measurement Time
Time Type
s, ms
Time elapsed between the last synchronisation signal and
measurement
Final Angular Rate
Real Vector Type
rad/s
w = vector(3) Reference frame: sensor frame vs inertial frame
Final Angular Rate
Measurement Time
Time Type
s, ms
Time elapsed between the last synchronisation signal and
measurement
Mode
Natural or Enum Type
-
Sensor mode
Direct Command
Natural or Enum Type
-
Command Id (e.g. reset, Standby)
Linear Velocity
Real Vector Type
m/s
S/C velocity vector = vector (3) in J2000 frame
Raw Attitude
Quaternion Type
-
Reference frame: J2000 frame --> sensor frame
Raw Linear Velocity
Int Vector Type
m/s
Velocity / Rc
SubNetwork Address
Natural Type
-
Global address of the unit among the subnetwork
Service Type
Natural or Enum Type
-
SOIS Service Id (e.g. PS, DAS)
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 6
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Example of EDS for DAS
Subset of EDS for SODERN HYDRA (DAS  Subnetwork)
Global subnetwork address is function of
the subnetwork type (i.e. Mil1553), STR
address within the subnetwork (i.e. RT
03), but also of the subnetwork
management policy.
EDS content for User (DAS)
EDS content for Target (Subnetwork)
CDD Item
Value
CDD Item
Value
–Device Id
–STR-A
–Subnet Addr
–STR address discovered by the
subnetwork services
–Service Type
–Packet Service
–Service Class
–Best Effort
…
–Service Primitive
–Acquire_From_Device
–Service Primitive
–Packet_Receive
–Value Id
–QRsFil
–Channel
–SAInfo
–Pkt Type
–Attitude Tracking Mode Telemetry
–Pkt Field Position
–Byte pos. 16
–Pkt Field Size
–32bytes
…
–Service Primitive
–Command_Device
–Service Primitive
–Packet_Send
–Value Id
–VabYc
–Channel
–IdUpdate
–Pkt Type
–Linear Velocity Update Command
–Pkt Field Position
–Byte pos. 8
–Pkt Field Size
–32bytes
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 7
ESA UNCLASSIFIED – For Official Use
Example of DAS implementation
using EDS information
To acquire the value Quat of QRsFil (filtered fused attitude quaternion), the Device
Access Service user shall invoke the following service primitives:
Acquire_From_Device.request(DASAP, TransId, STR-A, QRsFil);
…
Acquire_From_Device.indication(DASAP, TransId, Quat, ErrorCode);
DAS service primitives can then be implemented by means of Packet Service
primitives calls, for example as follows:
Acquire_From_Device.indication(DASAP, TransId, Val, ResultMeta)
{
Packet_Receive.indication(PSSAP, Mil-RT03, BE, SAInfo, PktData);
for (I = 0;I < Pkt Field Size; I++)
Val[I] = PktData[I + Byte Pos];
}
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 8
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In red, relevant output parameters
In blue, elements of the EDS
Example of EDS for DVS
Subset of EDS for SODERN HYDRA (DVS  DAS)
EDS content for User (DVS)
EDS content for Target (DAS)
CDD Item
Value
CDD Item
Value
–Device Id
–STR-Nom
–Device Id
–STR-A
–Service Primitive
–DVS_Acquire
–Service Primitive
–Acquire_From_Device
–Attribute Id
–Final Attitude
–Value Id
–QRsFil
–Conversion Law
–Identity
…
…
–Service Primitive
–DVS_Command
–Service Primitive
–Command_Device
–Attribute Id
–Linear Velocity
–Value Id
–VabXc
–Conversion Law
–Double-To-Int
–Service Primitive
–Command_Device
–Value Id
–VabYc
–Service Primitive
–Command_Device
–Value Id
–VabZc
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 9
ESA UNCLASSIFIED – For Official Use
Example of DVS implementation
using EDS
To command the update of the linear velocity (VabXc, VabYc, VabZc) to value Vel, the Device
Virtualisation Service user shall invoke the following service primitives:
DVS_Command(STR-Nom, Linear Velocity, Vel, ErrorCode);
DVS service primitives can then be implemented by means of DAS primitives calls, for example
as follows:
DVS_Command (Device Id, Attribute Id, Value, ResultMeta)
{
if (Device Id == STR-Nom)
Dev = STR-A;
else
Dev = STR-B;
More elaborated conversion law can be applied here
if (Attribute Id == Linear Velocity)
{
VelX = Double-To-Int(Value[0]);
In green, relevant input
VelY = Double-To-Int (Value[1]);
In blue, elements of the
VelZ = Double-To-Int (Value[2]);
Command_Device.request(DASAP, TransId0, Dev , VabXc, VelX);
Command_Device.request(DASAP, TransId1, Dev , VabYc, VelY);
Command_Device.request(DASAP, TransId2, Dev , VabZc, VelZ);
}
}
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 10
ESA UNCLASSIFIED – For Official Use
parameters
EDS
SOIS PnP Architecture - Recap
EDS contains different sections
covering the different SOIS
service/abstraction layers.
Its content is mainly filled in by
equipment manufacturer.
Applications
Device Virtualisation
Service
CDD
EDS
Device Enumeration
Service
Device Access
Service
Types to be defined with
the main contribution of
SAVOIR-SAFI WG.
Policy
Subnetwork
Management and
Configuration
Subnetwork
Device Discovery
Service
Subnetwork
Packet or Memory
Access Service
Subnetwork
Plug-and-Play
Protocol
Subnetwork
Protocol
Implementations
Hardware
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 11
ESA UNCLASSIFIED – For Official Use
Device specific functional
interface, uses the
existing equipment
capabilities and fits in
the SAVOIR-FAIRE SW
architecture.
SOIS
Framework,
specifications of formats
and mechanisms need to
be defined by SOIS WG
to enable definition and
usage of CDD, EDS and
C&DA services.
Subnetwork
Implementation
Summary
–
Examples of CDD and EDS using elements of the provided Star Tracker TM/TC
ICD have been presented as well as a possible service implementation.
–
EDS, DVS and DAS allow flexibility in the usage and implementation, still
preserving standard service interfaces.
–
DAS interface (device specific functional interface) and the related sections
of the EDS can be defined and used with the existing equipments
without modifications.
–
The mechanisms to access CDD and EDS and their formats are under
definition by the SOIS WG.
–
The implementation of DAS and DVS can easily follow a recurrent design
pattern, which would in the future also enable auto-coding of part of the
services and user applications.
–
SAVOIR-SAFI in the short term would be very helpful in contributing to
the definition of the Common Data Dictionary content (semantic and
syntactic types) in order to represent the interfaces of the existing
equipments.
Example of SOIS EDS | F. Torelli | ESTEC | 23/06/2011 | Slide 12
ESA UNCLASSIFIED – For Official Use