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55 lines
1.6 KiB
Plaintext
55 lines
1.6 KiB
Plaintext
=== Container Specifiers
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A *container specifier* specifies a data product container as part of a
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<<Definitions_Component-Definitions,component definition>>.
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Containers are units of data that can be downlinked and then deleted.
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They hold <<Specifiers_Record-Specifiers,data product records>>.
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==== Syntax
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`product` `container` <<Lexical-Elements_Identifiers,_identifier_>>
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_[_
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`id` <<Expressions,_expression_>>
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_]_
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_[_
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`default` `priority` <<Expressions,_expression_>>
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_]_
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==== Semantics
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. The identifier names the container.
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. The optional expression _e_ after the keyword `id` specifies the
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numeric identifier for the container.
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If _e_ is present, then the type of _e_ must be
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<<Type-Checking_Type-Conversion,convertible to>>
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<<Types_Internal-Types_Integer,_Integer_>>, and _e_ must evaluate
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to a nonnegative integer.
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If _e_ is not present, then the
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default identifier is either zero (for the first container appearing in a
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component) or the previous container identifier plus one.
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. The optional expression _e_ after the keywords `default` `priority`
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specifies a downlink priority for the container.
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This priority can be overridden by the command that downlinks the data.
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If _e_ is present, then the type of _e_ must be
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<<Type-Checking_Type-Conversion,convertible to>>
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<<Types_Internal-Types_Integer,_Integer_>>, and _e_ must evaluate
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to a nonnegative integer.
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==== Examples
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[source,fpp]
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----
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@ Container 0
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@ Implied id is 0x00
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product container Container0
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@ Container 1
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product container Container1 id 0x02
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@ Container 2
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@ Implied id is 0x03
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product container Container2 default priority 10
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----
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