FPP JSON Dictionary Specification

This document describes the format of FPP JSON dictionaries.

Type Descriptors
Constants
Type Definitions
Values
Commands, Telemetry Channels, Events, and Parameters
Data Products
- Records
- Containers
Telemetry Packet Sets
- Telemetry Packets
- Telemetry Packet Sets
Dictionaries

Type Descriptors

A Type Descriptor is a JSON Dictionary that describes a type.

Primitive Integer Type Descriptors

Field	Description	Options	Required
`name`	String representing the FPP type name	`U8`, `U16`, `U32`, `U64`, `I8`, `I16`, `I32`, `I64`	true
`kind`	String representing the kind of type	`integer`	true
`size`	Number of bits supported by the data type	`8`, `16`, `32`, `64`	true
`signed`	Boolean indicating whether the integer is signed or unsigned	Boolean	true

Unsigned Integer Types

Example: Type Descriptor for U64

json

{
    "name": "U64",
    "kind": "integer",
    "size": 64,
    "signed": false,
}

Signed Integer Types

Example: Type Descriptor for I8

json

{
    "name": "I8",
    "kind": "integer",
    "size": 8,
    "signed": true,
}

Floating-Point Type Descriptors

Field	Description	Options	Required
`name`	String representing the FPP type name	`F32`, `F64`	true
`kind`	String representing the kind of type	`float`	true
`size`	Number of bits supported by the data type	`32`, `64`	true

Floating-Point Types

Example: Type Descriptor for F64

json

{
    "name": "F64",
    "kind": "float",
    "size": 64,
}

Boolean Type Descriptors

Field	Description	Options	Required
`name`	String representing the FPP type name	`bool`	true
`kind`	String representing the kind of type	`bool`	true
`size`	Number of bits supported by the data type	`8`	true

Boolean Types

true
false

Example: Type Descriptor for booleans

json

{
    "name": "bool",
    "kind": "bool",
    "size": 8
}

String Type Descriptors

Field	Description	Options	Required
`name`	String representing the FPP type name	`string`	true
`kind`	String representing the kind of type	`string`	true
`size`	Number representing the maximum string size in bytes	Number in the range [1, 2<sup>31</sup>)	true

String Types

Any sequence of characters

Example Type Descriptor for string

json

{
    "name": "string",
    "kind": "string",
    "size": 80,
}

Qualified Identifier Type Descriptors

A Qualified Identifier is a kind of Type Descriptor that refers to a Type Definition.

Field	Description	Options	Required
`name`	String representing the fully qualified FPP type name	Period-separated String	true
`kind`	String representing the kind of type	qualifiedIdentifier	true

Example JSON of qualified name

json

{
    "name": "Module1.MyArray",
    "kind": "qualifiedIdentifier",
}

Constants

Field	Description	Options	Required
`qualifiedName`	Fully qualified name of element in FPP model	Period-separated String	true
`type`	The type of the constant value	Type Descriptor	true
`value`	Value associated with the constant	Constant Value	true
`annotation`	User-defined annotation	String	false

Type information for integer constant dictionary entries is determined by checking the sign of a constant and will always default to the maximum integer size (64 bits):

If the constant is positive, the type of the constant is U64.
If the constant is negative, the type of the constant is I64.

Example FPP model with JSON representation:

module M1 {
  @ Constant with value 1
  constant C = 1
}

json

{
  "qualifiedName" : "M1.C",
  "type" : {
    "name" : "U64",
    "kind" : "integer",
    "size" : 64,
    "signed" : false
  },
  "value" : 1,
  "annotation" : "Constant with value 1"
}

Type Definitions

Array Type Definition

Field	Description	Options	Required
`kind`	The kind of type	`array`	true
`qualifiedName`	Fully qualified name of element in FPP model	Period-separated String	true
`size`	Size of the data structure	Number	true
`elementType`	The type of the array's elements	Type Descriptor	true
`default`	Default array value	Array Value	true
`annotation`	User-defined annotation	String	false

Example FPP model with JSON representation:

module M1 {
    @ My array named A
    array A = [3] U8
}

json

{
    "kind": "array",
    "qualifiedName": "M1.A",
    "size": 3,
    "elementType": {
        "name": "U8",
        "kind": "integer",
        "signed": false,
        "size": 8
    },
    "default": [0, 0, 0],
    "annotation": "My array named A"
}

Enumeration Type Definition

Field	Description	Options	Required
`kind`	The kind of type	`enum`	true
`qualifiedName`	Fully qualified name of element in FPP model	Period-separated String	true
`representationType`	Type of the enumerated values	Type Descriptor	true
`enumeratedConstants`	The enumerated constants	JSON Dictionary of enumerated constants (keys) to Enumerated Constant Descriptor (values)	true
`default`	Qualified name of the enumeration's default value	Enumeration Value	true
`annotation`	User-defined annotation	String	false

Enumerated Constant Descriptors

Field	Description	Options	Required
`name`	Name of the enumerated constant	String	true
`value`	Value associated to the enumerated constant	Number	true
`annotation`	User-defined annotation for the enumerated constant	String	false

Example FPP model with JSON representation:

module M1 {
    @ Schroedinger's status
    enum Status {
        YES
        NO
        MAYBE @< The cat would know
    } default MAYBE
}

json

{
    "kind": "enum",
    "qualifiedName": "M1.Status",
    "representationType": {
        "name": "I32",
        "kind": "integer",
        "signed": true,
        "size": 32
    },
    "enumeratedConstants": [
        {
            "name": "YES",
            "value" : 0
        },
        {
            "name": "NO",
            "value" : 1
        },
        {
            "name" : "MAYBE",
            "value" : 2,
            "annotation": "The cat would know"
        },
    ],
    "default": "M.Status.MAYBE",
    "annotation": "Schroedinger's status"
}

Struct Type Definition

Field	Description	Options	Required
`kind`	The kind of type	`struct`	true
`qualifiedName`	Fully qualified name of element in FPP model	Period-separated String	true
`members`	The members of the struct	JSON dictionary of Member Name (key) to Struct Member Descriptor (value)	true
`default`	The default value of the struct	Struct Value	true
`annotation`	User-defined annotation	String extracted from FPP model	false

Struct Member Descriptor

Field	Description	Options	Required
`type`	Type Descriptor of member	Type Descriptor	true
`index`	Index of the struct member	Number	true
`size`	Size of the struct member	Number	false
`format`	Format specifier	String	false
`annotation`	User-defined annotation	String extracted from FPP model	false

Example FPP model with JSON representation:

module M1 {
    @ Struct for wxy values
    struct S {
        w: [3] U32 @< This is an array
        x: U32
        y: F32
    }
}

json

{
    "kind": "struct",
    "qualifiedName": "M1.S",
    "members": {
        "w": {
            "type": {
              "name": "U32",
              "kind": "integer",
              "size": 32,
              "signed": false,
            },
            "index": 0,
            "size": 3,
            "annotation" : "This is an array"
        },
        "x": {
            "type": {
                "name": "U32",
                "kind": "integer",
                "signed": false,
                "size": 32
            },
            "index": 1,
            "format": "the count is {}",
        },
        "y": {
            "type": {
                "name": "F32",
                "kind": "float",
                "size": 32
            },
            "index": 2
        }
    },
    "default": {
        "w": [0, 0, 0],
        "x": 0,
        "y": 0
    },
    "annotation": "Struct for wxy values"
}

Type Alias Definition

Field	Description	Options	Required
`kind`	The kind of type	`alias`	true
`qualifiedName`	Fully qualified name of element in FPP model	Period-separated String	true
`type`	Type Descriptor of the alias	Type Descriptor	true
`underlyingType`	Type Descriptor of the underlying type of the alias	Type Descriptor	true
`annotation`	User-defined annotation	String extracted from FPP model	false

Example FPP model with JSON representation:

module M1 {
    @ Alias of type U32
    type A1 = U32
    @ Alias of type A1
    type A2 = A1
}

json

[
  {
    "kind": "alias",
    "qualifiedName": "M1.A1",
    "type": {
      "name": "U32",
      "kind": "integer",
      "signed": false,
      "size": 32
    },
    "underlyingType": {
      "name": "U32",
      "kind": "integer",
      "signed": false,
      "size": 32
    },
    "annotation": "Alias of type U32"
  },
  {
    "kind": "alias",
    "qualifiedName": "M1.A2",
      "type": {
        "name": "M1.A1",
        "kind": "qualifiedIdentifier"
      },
      "underlyingType": {
        "name": "U32",
        "kind": "integer",
        "signed": false,
        "size": 32
      },
    "annotation": "Alias of type A2"
  }
]

Values

The type of a value follows the same typing rules as FPP, except for the type of struct values, which is described in the Struct Values section below.

Primitive Integer Values

Number representing integer value

Example JSON of type U8 with a value of 2:

json

Example JSON of type I8 with a value of -2:

json

-2

Floating-Point Values

Number representing float value

Example JSON of type F32 with a value of 10.0

json

10.5

Boolean Values

Boolean value

Example JSON of type bool with a value of true

json

true

String Values

String containing sequence of characters

Example JSON of type string with a value of "Hello World!"

json

"Hello World!"

Array Values

Array of elements with type and array size corresponding to the element type and size specified in the Array Type Definition.

Example JSON of an array of type U32 consisting of 10 elements

json

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Constant Values

Constant values include Primitive Integer, Floating-Point, String, and Boolean values.

Enumeration Values

String qualified identifier name of enumeration value

Example JSON of an enum

json

"Status.YES"

Struct Values

JSON Dictionary mapping struct member names to their values. Each key in the dictionary corresponds to a struct member name. The type of the value associated with each key matches the type specified in the Struct Member. If the struct member does not specify a size, then the value is a single value of that type. If the struct member does specify a size, then the value is an array of size elements, where each element is a value of the type specified for the member.

Example FPP struct:

struct S {
  W: [3] U32 @< This is an array
  X: U32
  Y: string
  Z: F32
} default { 
  W = 1, 
  X = 20, 
  Y = "Hello World!", 
  Z = 15.5 
}

Example JSON of a struct default value:

json

{
    "W": [1, 1, 1],
    "X": 20,
    "Y": "Hello World!",
    "Z": 15.5
}

Invalid Values

Null Values

Field	Description	Options	Required
`name`	String indicating that the value is null	null	true
`kind`	String indicating that the kind of value is invalid	invalid	true

Infinity Values

Field	Description	Options	Required
`name`	String indicating that the value is infinity	infinity	true
`kind`	String indicating that the kind of value is invalid	invalid	true

Negative Infinity Values

Field	Description	Options	Required
`name`	String indicating that the value is negative infinity	negativeInfinity	true
`kind`	String indicating that the kind of value is invalid	invalid	true

Commands, Telemetry Channels, Events, and Parameters

Formal Parameters

Formal Parameters are used in Commands and Events definitions.

Field	Description	Options	Required
`name`	Name of parameter	String	true
`type`	Type Descriptor of parameter	Type Descriptor	true
`ref`	Boolean indicating whether the formal parameter is to be passed by referenced when it is used in a synchronous port invocation	Boolean	true
`annotation`	User-defined annotation of parameter	String	false

json

{
    "name": "param1",
    "type": {
        "name": "U32",
        "kind": "integer",
        "size": 32,
        "signed": false,
    },
    "ref": false,
    "annotation": "This is param1"
}

Commands

Field	Description	Options	Required
`name`	Fully qualified name of the command	Period-separated String	true
`commandKind`	The kind of command	`async`, `guarded`, `sync`, `set`, `save`	true
`opcode`	Command opcode	Number	true
`formalParams`	Parameters of the command	Array of Formal Parameters	true
`annotation`	User-defined annotation of command	String	false
`priority`	Priority for the command on the input queue	Number	required for async command kinds
`queueFullBehavior`	Behavior of the command when the input full is queue	`assert`, `block`, `drop`	required for async command kinds

Example Command in FPP:

module M {

  active component Component1 { 

    @ A sync command with parameters
    sync command SyncParams(
        param1: U32 @< Param 1
        param2: string @< Param 2
    ) opcode 0x01

  }

  instance c1: Component1 base id 0x100 \
    queue size 10

  topology T {
    instance c1
  }

}

JSON representation:

json

{
    "name": "M.c1.SyncParams",
    "commandKind": "sync",
    "opcode": 257,
    "annotation": "A sync command with parameters",
    "formalParams": [
        {
            "name": "param1",
            "annotation": "Param 1",
            "type": {
                "name": "U32",
                "kind": "integer",
                "size": 32,
                "signed": false,
            },
            "ref": false
        },
         {
            "name": "param2",
            "annotation": "Param 2",
            "type": {
                "name": "string",
                "kind": "string",
                "size": "80"
            },
            "ref": false
        }
    ],
}

Telemetry Channels

Field	Description	Options	Required
`name`	Fully qualified name of the telemetry channel	Period-separated String	true
`type`	Type Descriptor of the telemetry channel	Type Descriptor	true
`id`	Numeric identifier of the channel	Number	true
`telemetryUpdate`	Update specifier of the telemetry channel	`always`, `on change`	true
`format`	Format string of the channel	String	false
`annotation`	User-defined annotation of channel	String	false
`limit`	Low and high limits of the channel	JSON dictionary	false

Example FPP model with JSON representation:


module M {

  active component Component1 { 

    @ Telemetry channel 1
    telemetry Channel1: F64 \
      id 0x02 \
      update on change \
      low { yellow -1, orange -2, red -3 } \
      high { yellow 1, orange 2, red 3 }

  }

  instance c1: Component1 base id 0x100 \
    queue size 10

  topology T {
    instance c1
  }

}

json

[
    {
        "name": "M.c1.Channel1",
        "annotation": "Telemetry channel 1",
        "type": {
            "name": "F64",
            "kind": "float",
            "size": 64
        },
        "id": 258,
        "telemetryUpdate": "on change",
        "limit": {
            "low": {
                "yellow": -1,
                "orange": -2,
                "red": -3
            },
            "high": {
                "yellow": 1,
                "orange": 2,
                "red": 3
            }
        }
    }
]

Events

Field	Description	Options	Required
`name`	Fully qualified name of the event	Period-separated String	true
`severity`	Severity of the event	`ACTIVITY_HI`, `ACTIVITY_LO`, `COMMAND`, `DIAGNOSTIC`, `FATAL`, `WARNING_HI`, `WARNING_LO`	true
`formalParams`	Parameters of the event	Array of Formal Parameters	true
`id`	Numeric identifier of the event	Number	true
`format`	Format string of the event	String	true
`throttle`	Maximum number of times to emit the event before throttling it	Number	false
`annotation`	User-defined annotation of the event	String	false

Example FPP model with JSON representation:

module M {

  active component Component1 { 

    @ This is the annotation for Event 1
    event Event1(
      arg1: U32 @< Argument 1
    ) \
      severity activity low \
      id 0x03 \
      format "Event 1 occurred"

  }

  instance c1: Component1 base id 0x100 \
    queue size 10

  topology T {
    instance c1
  }

}

json

{
    "name": "M.c1.Event1",
    "annotation": "This is the annotation for Event 1",
    "severity": "ACTIVITY_LO",
    "formalParams": [
      {
        "name": "arg1",
        "annotation": "Argument 1",
        "type": {
            "name": "U32",
            "kind": "integer",
            "size": 32,
            "signed": false,
        },
        "ref": false  
      }
    ],
    "id": 259,
    "format": "Event 1 occurred",
}

Parameters

Field	Description	Options	Required
`name`	Fully qualified name of the parameter	Period-separated String	true
`type`	Type Descriptor of the parameter	Type Descriptor	true
`id`	Numeric identifier of the parameter	Number	true
`default`	Default value (of type specified in `type`) of the parameter	Value of type specified in `type`	false
`annotation`	User-defined annotation of parameter	String	false

Example FPP model with JSON representation:


module M {

  active component Component1 { 

    @ This is the annotation for Parameter 1
    param Parameter1: U32 \
      id 0x04 \

  }

  instance c1: Component1 base id 0x100 \
    queue size 10

  topology T {
    instance c1
  }

}

json

{
    "name": "M.c1.Parameter1",
    "type": {
        "name": "U32",
        "kind": "integer",
        "signed": false,
        "size": 32
    },
    "id": "260",
    "annotation": "This is the annotation for Parameter 1",
    "default": 0
}

Data Products

Records

Field	Description	Options	Required
`name`	Fully qualified name of the record	Period-separated String	true
`type`	Type Descriptor the record	Type Descriptor	true
`array`	Boolean specifying whether the record stores a variable number of elements	Boolean	true
`id`	The numeric identifier of the record	Number	true
`annotation`	User-defined annotation of record	String	false

Example FPP model with JSON representation:

module M {

  active component Component1 { 

    @ Record 0: A variable number of F32 values
    product record Record0: F32 array id 0x05

    @ Record 1: A single U32 value
    product record Record1: U32 id 0x06

  }

  instance c1: Component1 base id 0x100 \
    queue size 10

  topology T {
    instance c1
  }

}

json

[
    {
        "name": "M.c1.Record0",
        "annotation": "Record 0: A variable number of F32 values",
        "type": {
            "name": "F32",
            "kind": "float",
            "size": 32
        },
        "array": true,
        "id": 261 
    },
    {
        "name": "M.c1.Record1",
        "annotation": "Record 1: A single U32 value",
        "type": {
            "name": "U32",
            "kind": "integer",
            "signed": false,
            "size": 32
        },
        "array": false,
        "id": 262
    }      
]

Containers

Field	Description	Options	Required
`name`	Fully qualified name of the container	Period-separated String	true
`id`	The numeric identifier of the record	Number	true
`defaultPriority`	The downlink priority for the container	Number	false
`annotation`	User-defined annotation of container	String	false

Example FPP model with JSON representation:

module M {

  active component Component1 { 

    @ Container 0
    product container Container0 id 0x07

    @ Container 1
    product container Container1 id 0x08

    @ Container 2
    product container Container2 id 0x09 default priority 10

  }

  instance c1: Component1 base id 0x100 \
    queue size 10

  topology T {
    instance c1
  }

}

json

[
    {
       "name": "M.c1.Container0",
       "annotation": "Container 0",
       "id": 263,
    },
    {
        "name": "M.c1.Container1",
        "annotation": "Container 1",
        "id": 264,
    },
    {
        "name": "M.c1.Container2",
        "annotation": "Container 2",
        "id": 265,
        "defaultPriority": 259
    }
]

Telemetry Packet Sets

Telemetry Packets

Field	Description	Options	Required
`name`	Name of the telemetry packet	String	true
`id`	Numeric identifier of the packet	Number	true
`group`	Packet group number	Number	true
`members`	Telemetry Channels in the packet	Array of Fully Qualified Names of Telemetry Channels	true

Telemetry Packet Sets

Field	Description	Options	Required
`name`	Name of the telemetry packet set	String	true
`members`	Telemetry Packets in the set	Array of Telemetry Packets	true
`omitted`	Telemetry Channels omitted from the set	Array of Fully Qualified Names of Telemetry Channels	true

Example FPP model with JSON representation:

module M {

  active component Component1 {
    @ Telemetry channel 0
    telemetry Channel0: U32 id 0x00

    @ Telemetry channel 1
    telemetry Channel1: U32 \
      id 0x01 \
      update on change

    @ Telemetry channel 2
    telemetry Channel2: F64 \
      id 0x02 \
      format "{.3f}"
  }

  instance c1: Component1 base id 0x100 \
    queue size 10

  topology T {
    instance c1

    telemetry packets Packets {
      packet P1 id 0 level 0 {
        M.c1.Channel0
        M.c1.Channel1
      }
    } omit {
      M.c1.Channel2
    }
  }
}

json

[
  {
      "name" : "Packets",
      "members" : [
        {
          "name" : "P1",
          "id" : 0,
          "group" : 0,
          "members" : [
            "M.c1.Channel0",
            "M.c1.Channel1"
          ]
        }
      ],
      "omitted" : [
        "M.c1.Channel2"
      ]
    }
]

Dictionaries

Dictionary Metadata

Field	Description	Options	Required
`deploymentName`	String representing the fully qualified name of the topology	String	true
`frameworkVersion`	String representing the F´ framework version (semantic versioning)	String	true
`projectVersion`	String representing the project version (semantic versioning)	String	true
`libraryVersions`	Array of Strings corresponding to the version (semantic versioning) of libraries used by the F´ project	Array of Strings	true
`dictionarySpecVersion`	String representing the JSON dictionary specification version	String	true

json

{
    "deploymentName": "MyDeployment",
    "frameworkVersion": "3.3.2",
    "projectVersion": "1.0.0",
    "libraryVersions": [],
    "dictionarySpecVersion": "1.0.0"
}

Dictionary Content

Field	Content	Required
`metadata`	Dictionary Metadata	true
`typeDefinitions`	Array of Type Definitions	true
`constants`	Array of Constants	true
`commands`	Array of Commands	true
`events`	Array of Events	true
`telemetryChannels`	Array of Telemetry Channels	true
`parameters`	Array of Parameters	true
`records`	Array of Records	true
`containers`	Array of Containers	true
`telemetryPacketSets`	Array of Telemetry Packet Sets	true

Example FPP model with JSON representation:

module M {

  array StringArray = [2] string size 80 default [ "A", "B"]

  enum StatusEnum {
    YES
    NO
    MAYBE
  } default MAYBE

  struct A {
    x: U32 format "The value of x is {}"
    y: [2] F32 format "The value of y is {}"
  } default { x = 1, y = 1.15 }


  active component Component1 { 

    @ A command with a single StringArray argument
    sync command CommandString(
        arg1: M.StringArray @< description for argument 1
    ) opcode 0x01

    @ This is the annotation for Parameter 1
    param Parameter1: A \
      id 0x02 \
      set opcode 0x03 \
      save opcode 0x04

    @ Event with one StatusEnum argument
    event Event1(
      arg1: M.StatusEnum @< Description of arg1 formal param
    ) \
      severity activity high \
      id 0x05 \
      format "Event 1 occurred, status {}"

    @ Telemetry channel 1 of type I32
    telemetry Channel1: I32 \
      id 0x06 \
      update on change \
      low { yellow -1, orange -2, red -3 } \
      high { yellow 1, orange 2, red 3 }

    @ Record 0: A variable number of F32 values
    product record Record0: F32 array id 0x05

    @ Record 1: A single U32 value
    product record Record1: U32 id 0x06

    @ Container 0
    product container Container0 id 0x07

    @ Container 1
    product container Container1 id 0x08

    @ Container 2
    product container Container2 id 0x09 default priority 10

  }

  instance c1: Component1 base id 0x100 \
    queue size 10

  topology T {
    instance c1

    telemetry packets Packets {
      packet P1 id 0 level 0 {
        M.c1.Channel1
      }
    }
  }
}

json

{
  "metadata": {
    "deploymentName": "M.T",
    "frameworkVersion": "3.3.2",
    "projectVersion": "1.0.0",
    "libraryVersions": [],
    "dictionarySpecVersion": "1.0.0"
  },
  "typeDefinitions" : [
    {
      "kind" : "array",
      "qualifiedName" : "M.StringArray",
      "size" : 2,
      "elementType" : {
        "name" : "string",
        "kind" : "string",
        "size" : 80
      },
      "default" : [
        "A",
        "B"
      ],
      "annotation" : "An array of 2 String values"
    },
    {
      "kind" : "enum",
      "qualifiedName" : "M.StatusEnum",
      "representationType" : {
        "name" : "U8",
        "kind" : "integer",
        "size" : 8,
        "signed" : false
      },
      "enumeratedConstants" : [
        {
          "name" : "YES",
          "value" : 0
        },
        {
          "name" : "NO",
          "value" : 1
        },
        {
          "name" : "MAYBE",
          "value" : 2
        }
      ],
      "default" : "M1.StatusEnum.MAYBE"
    },
    {
      "kind" : "struct",
      "qualifiedName" : "M.A",
      "members" : {
        "x" : {
          "type" : {
            "name" : "U32",
            "kind" : "integer",
            "size" : 32,
            "signed" : false
          },
          "index" : 0,
          "format" : "The value of x is {}"
        },
        "y" : {
          "type" : {
            "name" : "F32",
            "kind" : "float",
            "size" : 32
          },
          "index" : 1,
          "size": 2,
          "format" : "The value of y is {}"
        }
      },
      "default" : {
        "x" : 1,
        "y" : [1.15, 1.15]
      }
    }
  ],
  "constants": [],
  "commands" : [
    {
      "name" : "M.c1.CommandString",
      "commandKind" : "sync",
      "opcode" : 257,
      "formalParams" : [
        {
          "name" : "arg1",
          "type" : {
            "name" : "M.StringArray",
            "kind" : "qualifiedIdentifier"
          },
          "ref" : false,
          "annotation" : "description for argument 1"
        }
      ],
      "annotation" : "A command with a single StringArray argument"
    },
    {
      "name" : "M.c1.Parameter1_PRM_SET",
      "commandKind" : "set",
      "opcode" : 259,
      "formalParams" : [
        {
          "name" : "val",
          "type" : {
            "name" : "M.A",
            "kind" : "qualifiedIdentifier"
          },
          "ref" : false
        }
      ],
      "annotation" : "Parameter (struct)"
    },
    {
      "name" : "M.c1.Parameter1_PRM_SAVE",
      "commandKind" : "save",
      "opcode" : 260,
      "formalParams" : [
      ],
      "annotation" : "Parameter (struct)"
    }
  ],
  "parameters" : [
    {
      "name" : "M.c1.Parameter1",
      "type" : {
        "name" : "M.A",
        "kind" : "qualifiedIdentifier"
      },
      "id" : 258,
      "default" : {
        "x" : 1,
        "y" : 1.15
      },
      "annotation" : "Parameter (struct)"
    }
  ],
  "events" : [
    {
      "name" : "M.c1.Event1",
      "severity" : "ACTIVITY_HI",
      "formalParams" : [
        {
          "name" : "arg1",
          "type" : {
            "name" : "M.StatusEnum",
            "kind" : "qualifiedIdentifier"
          },
          "ref" : false,
          "annotation" : "Description of arg1 formal param"
        }
      ],
      "id" : 259,
      "format" : "Event 1 occurred, status {}",
      "annotation" : "Event with one StatusEnum argument"
    }
  ],
  "telemetryChannels" : [
    {
      "name" : "M.c1.Channel1",
      "type" : {
        "name" : "I32",
        "kind" : "integer",
        "size" : 32
      },
      "id" : 260,
      "telemetryUpdate" : "on change",
      "annotation" : "Telemetry channel 1 of type I32",
      "limit": {
        "low": {
          "yellow": "-1",
          "orange": "-2",
          "red": "-3"
        },
        "high": {
          "yellow": "1",
          "orange": "2",
          "red": "3"
        }
      }
    }
  ],
  "records" : [
    {
        "name": "M.c1.Record0",
        "annotation": "Record 0: A variable number of F32 values",
        "type": {
            "name": "F32",
            "kind": "float",
            "size": 32
        },
        "array": true,
        "id": 261 
    },
    {
        "name": "M.c1.Record1",
        "annotation": "Record 1: A single U32 value",
        "type": {
            "name": "U32",
            "kind": "integer",
            "signed": false,
            "size": 32
        },
        "array": false,
        "id": 262
    }   
  ],
  "containers" : [
    {
       "name": "M.c1.Container0",
       "annotation": "Container 0",
       "id": 263,
    },
    {
        "name": "M.c1.Container1",
        "annotation": "Container 1",
        "id": 264,
    },
    {
        "name": "M.c1.Container2",
        "annotation": "Container 2",
        "id": 265,
        "defaultPriority": 10
    }
  ],
  "telemetryPacketSets": [
    {
      "name" : "Packets",
      "members" : [
        {
          "name" : "P1",
          "id" : 0,
          "group" : 0,
          "members" : [
            "M.c1.Channel1"
          ]
        }
      ],
      "omitted" : []
    }
  ]
}

Framework Definitions Required by the Dictionary

The following framework definitions are required by the dictionary and will always be present in the dictionary content:

Name	Kind	Location	Purpose
`FwChanIdType`	Alias type definition	`typeDefinitions`	The type of a telemetry channel identifier
`FwEventIdType`	Alias type definition	`typeDefinitions`	The type of an event identifier
`FwOpcodeType`	Alias type definition	`typeDefinitions`	The type of a command opcode
`FwPacketDescriptorType`	Alias type definition	`typeDefinitions`	The type of a com packet descriptor
`FwDpIdType`	Alias type definition	`typeDefinitions`	The type of a data product identifier
`FwDpPriorityType`	Alias type definition	`typeDefinitions`	The type of a data product priority
`FwSizeStoreType`	Alias type definition	`typeDefinitions`	The type used to serialize a size value
`FwTimeBaseStoreType`	Alias type definition	`typeDefinitions`	The type used to serialize a time base value
`FwTimeContextStoreType`	Alias type definition	`typeDefinitions`	The type used to serialize a time context value
`Fw.DpState`	Enum type definition	`typeDefinitions`	The data product state
`Fw.DpCfg.ProcType`	Enum type definition	`typeDefinitions`	A bit mask for selecting the type of processing to perform on a container before writing it to disk.
`Fw.DpCfg.CONTAINER_USER_DATA_SIZE`	Constant Definition	`constants`	The size in bytes of the user-configurable data in the container packet header
`FW_FIXED_LENGTH_STRING_SIZE`	Constant Definition	`constants`	Configuration for Fw::String

FPP JSON Dictionary Specification

FPP JSON Dictionary Specification

Contents

Type Descriptors

Primitive Integer Type Descriptors

Unsigned Integer Types

Signed Integer Types

Floating-Point Type Descriptors

Floating-Point Types

Boolean Type Descriptors

Boolean Types

String Type Descriptors

String Types

Qualified Identifier Type Descriptors

Constants

Type Definitions

Array Type Definition

Enumeration Type Definition

Enumerated Constant Descriptors

Struct Type Definition

Struct Type Definition

Struct Member Descriptor

Type Alias Definition

Values

Primitive Integer Values

Floating-Point Values

Boolean Values

String Values

Array Values

Constant Values

Enumeration Values

Struct Values

Invalid Values

Null Values

Infinity Values

Negative Infinity Values

Commands, Telemetry Channels, Events, and Parameters

Formal Parameters

Commands

Telemetry Channels

Events

Parameters

Data Products

Records

Containers

Telemetry Packet Sets

Telemetry Packets

Telemetry Packet Sets

Dictionaries

Dictionary Metadata

Dictionary Content

Framework Definitions Required by the Dictionary