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 theDatapoint
object. In such case the attributes defined inside theDatapoint
object takes precedence overFeed
object level ones. For exampleloc
object defined inFeed
can be overwritten by anotherloc
object defined inside theDatapoint
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.
Updated over 7 years ago
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