JSON

Structure¶

The JSON format for frequency spectra is as follows:

[
    {
        "mappingId": "mappingId",
        "timestamp": "2024-03-04T18:13:00Z",
        "amplitudeUnit": "mm/s",
        "spacing": 1.0,
        "end": 4.0,
        "number": 5,
        "data": [
            0,
            1,
            2,
            3,
            4
        ],
        "speed": 1.0,
        "measurementType": "acceleration"
        |
        "velocity"
    }
]

[{
    "sensorId":         "sensorId",
    "timestamp":        "2024-03-04T18:13:00Z",
    "amplitudeUnit":    "mm/s",
    "spacing":          1.0,
    "end":              4.0,
    "number":           5,
    "data":             [0, 1, 2, 3, 4],
    "speed":            1.0,
    "measurementType":  "acceleration" | "velocity"
}]

• The mappingId is a unique mapping ID for a sensor. If a sensor with the mapping ID does not exist, a new sensor will be provisioned.
• The sensorId is a UUID that Senseye has allocated to a sensor. This field is used only if the sensor already exists.
• The timestamp should be in RFC3339 dates and times, including timezone - more details on the required format are available here.
• It is assumed that the data starts at 0 Hz.
• The amplitudeUnit should be a string value representing the units of measurement for the amplitude. For velocity, 'in/s', 'mm/s' and 'm/s' are valid units. For acceleration, 'in/s^2', 'mm/s^2' and 'm/s^2' are valid units. Conversion must be undertaken to one of these units prior to sending data to Senseye.
• The spacing details the gap between bins in Hz i.e. here 1Hz
• The end details the frequency at the last value in Hz i.e. here 4Hz
• The number is the number of points in the spectrum i.e. here 5.
• The speed is the speed of the machine, or reference frequency, in Hz i.e. here 2Hz
• The data field is a comma separated list of points, wrapped in escaped quote marks. The data is interpreted as a list of 64-bit floating point values. The number of these must match the number parameter.

File¶

Name¶

To avoid file collisions, the name of the file should be unique. To aid debugging, we recommend composing the file name using two components: an ID for the asset or group of assets being monitored, and a unix timestamp, separated by @ - as an example: motors@1651149458.json.

Size¶

Please limit the JSON request body to no more than 10MB.