Signal:

• An data entity defined by its identifier
• In practice we here mean the absolute path of the node in a VSS taxonomy

Record:

• A single measured data value
• Record types indicate which Signal has been measured,
• Record Types are used to represent data with associated metadata, as needed for different cases
• Example of types:
  • Just the value.
  • The value plus a timestamp
  • The value plus a timestamp plus a timestamp accuracy information
  • The value plus additional qualitative information

Snapshot:

• Several measured values, of different signals, each having a
  relationship to each other because they were measured "at the same time"
  (which means within a defined time period, of any chosen length)
• A snapshot is built up of several Records, and additional information

Bundle:

• Several measured values _of the same signal_, taken over a period of time.
• A bundle keeps track of the time stamp for each value
• A bundle is a collection of Records

Examples, in JSON

PlainRecord:

{
   "value" : " 100.54"
}

TimestampedRecord:

{
   "ts" : "20200319123245Z123456" # Zulu time ISO std + microsecond - to be clarified
   "value" : "42 "
}

Bundle:

{ 
    "signal"  :  "vehicle.body.cabin.temperature"
    "values" : {
        { 
            "ts" : "20200319123245Z123456"
            "value" : "42 "
        },
        { 
            "ts" : "20200320120101Z100000"
            "value" : "43"
        },
        ...
    }
}

Snapshot:

{ 
    "timeperiod" { 
        "start" : "xxx",
        "end" : "xxx"
    },
    "measurements" {
     {    
        "signal" : "vehicle.body.cabin.temperature",
        "value" : "42 ",
        "ts" : "20200320120101Z100000"
     },
     {    
        "signal"  :  "vehicle.drivetrain.engine.rpm.average",
        "value" : "42 ",
        "ts" : "20200320120101Z100000"
     }
}