Data Point

Attribute	Description
t	Reading time. The time when the data value is captured in ISO 8601 format - time zone designator is required.
v	Observed value (a.k.a reading). Should match to its destination property's type.
tt	Optional. A numeric value can be given as delta in milliseconds relative to base time given at feed level. Can be both negative and positive.
tags	Optional. Array of tags associated with the data point.
loc	Optional. The location where the data point is captured. See Location subresource for details.
prop	Optional. `id` or `name` of the destination property. This metadata is required by the system to identify the destination property when it cannot be inferred from the endpoint i.e. `POST .../v3/data/devices/{id or name}/properties`.
ann	Optional. The list of annotations (metadata) associated with this data point.

🚧
Rule
Some default attributes defined inside the Feed object level might overlap with the attributes defined within the Datapoint object. In such case the attributes defined inside the Datapoint object takes precedence over Feed object level ones. For example loc object defined in Feed can be overwritten by another loc object defined inside the Datapoint object.

It is highly recommended to move all repetitive information from data point level to Feed level using default attributes and annotations in order to minimize the data size on wire.

For example all three representations shown below are considered identical by the system.

{
  "dps": [
   { "t": "2017-05-01T14:00:37.575Z", "v": 23.45, 
    "ann": { "cusId": "C3434" }, "loc": { "zone": "factory1"}, "tags": ["test"]
   },
   { "t": "2017-05-01T14:00:37.645Z", "v": 23.65, 
    "ann": { "cusId": "C3434" }, "loc": { "zone": "factory1"}, "tags": ["test"]
   },
   { "t": "2017-05-01T14:00:37.775Z", "v": 24.01, 
    "ann": { "cusId": "C3434" }, "loc": { "zone": "factory1"}, "tags": ["test"]
   },
   { "t": "2017-05-01T14:00:37.885Z", "v": 23.99, 
    "ann": { "cusId": "C3434" }, "loc": { "zone": "factory1"}, "tags": ["test"]
   }
  ]
}

{
  "ann": { "cusId": "C3434" },
  "tags": ["test"], 
  "loc": { "zone": "factory1" },
  "dps": [
   {"t": "2017-05-01T14:00:37.575Z", "v": 23.45},
   {"t": "2017-05-01T14:00:37.645Z", "v": 23.65},
   {"t": "2017-05-01T14:00:37.775Z", "v": 24.01},
   {"t": "2017-05-01T14:00:37.885Z", "v": 23.99}
  ]
}

{
  "ann": { "cusId": "C3434" },
  "tags": ["test"], 
  "loc": { "zone": "factory1" },
  "t": "2017-05-01T14:00:37.645Z",
  "dps": [
   {"tt": -70, "v": 23.45},
   {"v": 23.65},               // "tt": 0 is not required
   {"tt": 130, "v": 24.01},
   {"tt": 240, "v": 23.99}
  ]
}

Some Data Point Examples

{
  "dps": [
   	{ "t": "2017-05-01T14:00:57.435Z", "v": 23.45, "prop": "temperature" },
   	{ "t": "2017-05-01T14:01:58.421Z", "v": 23.40, "prop": "temperature" },
   	{ "t": "2017-05-01T15:00:54.786Z", "v": 55, "prop":"humidity", "tags":["Fan345"]},
   	{ "t": "2017-05-01T15:01:56Z", "v": 65, "prop": "humidity"},
  ]
}

{
  "dps": [
   	{ 
      "t": "2015-05-01T14:00:57Z", 
      "v": { "geo": { "lat": 49.35, "lon": -123.07 } } }
   ]
}

📘
Tip
Waypoint properties are special and accept location object as value.