The FR Type
Specification Tool and
Applied Conventions
April 2016
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FR Type Properties
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FR Type Properties
• Semantic Definition: In addition to a brief
description of the functionality of the FR type, this
field also briefly describes input and output and
where applicable, the conditions under which
specific input data types can be handled
• Classifier: The string that identifies the FR type and
therefore also the OID assigned to the given type is
mandatory and now called “classifier”. By
convention, the Classifier string is written in
“camel case” (no white space, no hyphens). The
string is built using standard abbreviations, where
possible. FR type Classifiers commence with an
upper case letter.
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FR Type Properties
• String Identifier: Specification of such string is
optional and may be used e.g. for automated
document generation. How such string is built is at
least for now not constrained by specific
conventions.
• Version: Although the tool shows this property in
bold face, specification of the version is NOT
mandatory. On the contrary, versioning of FR types
is not supported and therefore insertion of the
version number does not affect the FR type OID.
• Creation Date: It is recommended that the Creation
Date reflects always the date when the most recent
update of the FR type specification has been made.
The tool does not perform this automatically.
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FR Type Properties
• Authorizing Entity: By default, this property shall
be set to “CSS Area”.
• OID Bit: This property displays the trailing number
of the FR type OID. OIDs can be generated
automatically based on the position of the FR type
in the tree or can be entered manually. WARNING:
Selective modification of OID numbers seems not
to work reliably. It is recommended to always enter
the complete OID.
• Deprecated Flag: If ticked, it means that this FR
type specification has been deprecated by CCSDS
and organization involved in cross support based
on FR type specifications should not expect such
FR type be supported very much longer by partner
organizations.
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FR Type Properties
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FR Type Properties
• Event, Directives, Parameter: These properties are
updated automatically, whenever a PED element is
added.
• Uses: By convention, this property specifies all FR
types from which the given FR type accepts input.
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FR Parameter Properties
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FR Parameter Properties
• If not stated differently here, what was stated
before regarding FR type properties also applies to
parameter properties
• Semantic Definition: The Semantic Definition of a
parameter shall make sure that the user can
ascertain unambiguously what the parameter
means in the given context
• Classifier: The string that identifies the parameter
where the first letter of the string shall be lower
case. The string shall be built using an FR type
specific prefix.
Note: Due to the serviceGenericIdentifiers OID
subtree, several classifiers may refer to the same
OID.
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FR Parameter Properties
• Version: The specification of the Version of a
parameter is mandatory. The version number forms
the last number of the parameter OID.
• OID Bit: In general, a parameter is a child of the
parent FR type and in that case the OID can be
generated by the tool. If the parameter is part of the
serviceGenericIdentifiers subtree, the OID must be
inserted manually. Note that this is not visible from
the properties view, but the Resource Set view.
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FR Parameter Properties
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FR Parameter Properties
• Type Definition:
Typically the type definition is one
of the CHOICEs specified by the TypeAndValue
ASN.1 type specified in the SFW.
If an externally defined type can be reused, that
type can be referenced by means of its OID.
specifying an external type OID. Such type
reference is not visible from the properties view,
but from the Resource set view. For convenience,
the type specification should be copied into the
properties view.
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FR Parameter Properties
• Engineering Unit: This property specifies the
engineering unit of the parameter. It may be scaled
such that the value can be conveniently expressed
as an integer. If no engineering unit applies, this
shall be expressed by the string “none”.
• “Configured” check box: This check box shall be
ticked if the parameter can be set by means of a
directive associated with the given FR type. If the
parameter can be monitored only, the check box
must not be ticked.
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FR Parameter Properties
• Guard Condition: If the parameter value can be
modified by means of a directive associated with
the given FR type only under certain conditions
(e.g. values of other parameters), this shall be
stated here. Preferably this shall be specified as a
formally expressed condition, but free text is
permitted. In case the parameter value may be
modified unconditionally, this shall be indicated by
the string “none”. If the “Configured” check box for
the given parameter is not ticked, a guard condition
must not be specified.
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FR Event Properties
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FR Event Properties
• For the properties that events and parameters have
in common, the specification provided for the FR
parameters is valid also for events except:
• Semantic Definition: The Semantic Definition of an
event shall specify the conditions that trigger the
notification of this event
• Value: If on top of the fact that the event has
triggered additional information shall be provided,
this is done by means of an event-value. When
such child of the event is specified, it is
automatically added to the Value property of the
event.
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FR (Event) Value Properties
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FR (Event) Value Properties
• An (Event) Value has almost the same properties as
an FR parameter, except that
• No OID is specified as it is not accessible e.g.
by a GET invocation
• There is no “Configured” check box and no
Guard Condition as the value is only reported,
but cannot be set
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FR Directive Properties
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FR Directive Properties
• For the Directive properties all considerations as
discussed before apply except for
• Semantic Definition: The Semantic Definition of a
directive shall specify which effect the invocation
of the directive has on the parent FR type.
• Qualifier: If additional information is necessary to
qualify the directive (e.g. which parameter shall be
set and to which value), this is done by means of a
directive qualifier. When such child of the directive
event is specified, it is automatically added to the
Qualifier property of the directive.
• Guard Condition: Her guard conditions shall be
specified in case the directive has no qualifier child
or the guard condition applies regardless of the
qualifier value(s).
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FR (Directive) Qualifier Properties
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FR (Directive) Qualifier Properties
• A (Directive) Qualifier has almost the same
properties as an FR parameter, except that
• No OID is specified as it is not accessible e.g.
by a GET invocation
• There is no “Configured” check box and no
Guard Condition as that is specified for each
parameter the directive may act on.
• Type Specification: Depending on the directive, the
Qualifier may have to support a variety of types.
Therefore rather than a specific type, the reference
chain of the ASN.1 may be specified.
• Engineering Unit: The Engineering Unit depends on
which kind of parameter(s) shall be set by means of
the directive and can therefore in most cases not
be specified.
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