Data selection parameters

topic

Required

string

The MQTT topic string. It cannot be null, empty, or whitespace.

valueField

Required

string

The JSONPath expression used to extract the data value from a property within the payload supplied by the MQTT server. A valid JSONPath expression starts with $.

Non-JSON can allow for a numeric value (such as 1, 2, etc.) depending on the array of data that is part of the message. For example, if you have a payload with three comma-separated values and are expecting to collect the second value, the valueField of that payload will be 2.

This parameter must not be left empty or contain only whitespace. valueField and dataFields are mutually exclusive, so it can be null only if the dataFields parameter is defined.

For more information about JSONPath expression syntax, see JSONPath syntax for value retrieval.

dataFields

Required

dictionary
<string, string>

A dictionary of values with key-value pairs. The keys are specific fields for a complex type and the values are the JSONPath expression used to extract the data value from a property within the payload supplied by the MQTT server. A valid JSONPath expression starts with $.

This parameter must not be left empty or contain only whitespace. valueField and dataFields are mutually exclusive, so it can be null only if the valueField parameter is defined.

Allowed keys: Latitude, Longitude, x, y, z.
Default value: null

For more information about JSONPath expression syntax, see JSONPath syntax for value retrieval.

indexField

Optional

string

The JSONPath expression to take value to use as a timestamp from a property. A valid JSONPath expression starts with $.

For more information about JSONPath expression syntax, see JSONPath syntax for value retrieval.

Note: The adapter generates a timestamp when null is specified.

Allowed value: Any valid JSONPath expression

dataType

Required

string

The expected data type of the values for the specified field.

Input MQTT data types are:

Int16, Int32, Int64, UInt16, UInt32, UInt64, Float32, Float64, Boolean, String, Date-Time

Input MQTT complex data types are: Geolocation and Coordinates.

For more information, see Principles of operation.

uom

Optional

string

A Unit of Measurement (UoM) is a reference point for measuring and comparing data, such as temperature or voltage.

The unit of measure value from a property within the payload supplied by the MQTT broker.

Allowed value: Any string
Default value: null

indexFormat

Optional

string

The time format of the timestamp value specified in the indexField property. The time format must be specified as yyyy-MM-ddTHH:mm:ss.

If you do not specify indexField and indexFormat, the adapter automatically sets the latter to Adapter, which uses an adapter-supplied timestamp for the data.

The timestamp is taken after the data is published to the adapter while the adapter processes it. If you specify indexFormat only with a value other than Adapter, the validation fails and the adapter triggers an error.

Default value: null

Allowed value: Any string that can be used as a DateTime format in the .NET DateTime.TryParseExact()method, for example, 01/30/2025.

For more information, see DateTime.TryParseExact Method.

Note: If the string cannot be parsed, specify a custom DateTime string or one of the following keywords: Adapter, UnixTimeSeconds, UnixTimeMilliseconds.

selected

Optional

boolean

Selects or clears a measurement. To select an item, set to true. To remove an item, leave the field empty or set to false.

Allowed value: true or false
Default value: false

name

Optional

string

The optional friendly name of the data item collected from the data source.

Allowed value: Any string
Default value: null

streamId

Optional

string

The custom stream Id that is used to create the streams.

If you do not specify the StreamId, the adapter generates a default stream Id based on the data source parameter. For more information, see Data source.

A properly configured custom stream Id follows these rules:

• Is not case-sensitive

• Can contain spaces

• Can contain front slashes (/)

• Can contain a maximum of 100 characters

• Cannot start with two underscores (__)

• Cannot start or end with a period

• Cannot contain consecutive periods

• Cannot consist of only periods

  The default Id automatically updates when there are changes to the measurement and follows the format of <Topic>.<MetricName>.

  For more information on how the adapter encodes special characters in the StreamId, see Egress endpoints.

dataFilterId

Optional

string

The identification of the data filter.

Allowed value: Any string
Default value: null

Note: If the specified dataFilterId does not exist, unfiltered data is sent until that dataFilterId is created.