GoogleIoTConnector

Input

This transformer accepts any feature.

Output

The output of this transformer will vary depending on the action performed. Message data and metadata are presented as feature attributes.

After a Subscribe action, output features represent messages received from Google IoT Core.
After a Publish action, output features represent messages sent to Google IoT Core.

Initiator

The incoming feature is output through this port.

Features that cause the operation to fail are output through this port. An fme_rejection_code attribute, having the value ERROR_DURING_PROCESSING, will be added, along with a more descriptive fme_rejection_message attribute which contains more specific details as to the reason for the failure.

Note If a feature comes in to the GoogleIoTConnector already having a value for fme_rejection_code, this value will be removed.

Rejected Feature Handling: can be set to either terminate the translation or continue running when it encounters a rejected feature. This setting is available both as a default FME option and as a workspace parameter.

Authentication

Credential Source

Using a web connection integrates best with FME, but in some cases, you may wish to use one of the other sources.

Web Connection - use a Google IoT web connection stored in the FME web connections database
Embedded - embed project ID and client private key as parameters in the transformer

Account

Available when the credential source is Web Connection. To create a Google IoT connection, click the 'Account' drop-down box and select 'Add Web Connection...'.

The connection can then be managed via Tools -> FME Options... -> Web Connections.

Certificates

CA Certificate

Google root CA certifications. This can be found at https://cloud.google.com/iot/docs/how-tos/mqtt-bridge#downloading_mqtt_server_certificates.

Request

Location	The region of the IoT Core registry. This is selected when creating the IoT Core registry.
Registry ID	The unique registry identifier for the IoT Core registry. This is created when creating the IoT Core registry.
Device ID	The unique identifier for the device. This is created when creating a device on Google IoT Core.
Action	The type of operation to perform. Choices are: Publish device state Publish telemetry events Subscribe to configuration updates Subscribe to device commands
QoS Level	The MQTT protocol allows a Quality of Service (QoS) level to be set. The following levels are available: At most once (level 0) At least once (level 1) Exactly once (level 2) The QoS guarantees are achieved by performing differing levels of client-server handshake. As a result, higher QoS levels are expected to lower throughput.

Parameters - Publish device state Action

Send Options

Payload

The content of the message. This is often JSON, but can be any string, binary, integer or floating-point value.

Parameters - Publish telemetry events Action

Send Options

Payload

The content of the message. This is often JSON, but can be any string, binary, integer or floating-point value.

Parameters - Subscribe to configuration updates Action

Receive Options

Receive Mode

Two message receiving options are available:

Stream: The connector continues to receive messages indefinitely. The translation needs to be terminated in order to stop reception.
Batch: Only a given number of messages are received before the connection is closed.

Batch Size

In Batch mode, specifies the number of messages to read per batch.

Parameters - Subscribe to device commands Action

Receive Options

Receive Mode

Two message receiving options are available:

Stream: The connector continues to receive messages indefinitely. The translation needs to be terminated in order to stop reception.
Batch: Only a given number of messages are received before the connection is closed.

Batch Size

In Batch mode, specifies the number of messages to read per batch.

Output Attributes

The following attributes can be selected for inclusion on the output features. Each output feature represents a message that was either sent or received.

_message_id	The sequential identifier for the message.
_payload	The message payload. UTF-8 string if possible to decode, otherwise binary or numeric.
_topic	The topic the message received from or sent to.
_qos	The quality of service level with which the message was sent or received.

How to Set Parameter Values

Defining Values

There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters.

Using the Text Editor

The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.

Text Editor

Using the Arithmetic Editor

The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.

Arithmetic Editor

Conditional Values

Set values depending on one or more test conditions that either pass or fail.

Parameter Condition Definition Dialog

Content

Expressions and strings can include a number of functions, characters, parameters, and more.

When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.

Content Types

String Functions	These functions manipulate and format strings.
Special Characters	A set of control characters is available in the Text Editor.
Math Functions	Math functions are available in both editors.
Date/Time Functions	Date and time functions are available in the Text Editor.
Math Operators	These operators are available in the Arithmetic Editor.
FME Feature Functions	These return primarily feature-specific values.
FME Parameters	FME and workspace-specific parameters may be used.
Creating and Modifying User Parameters	Create your own editable parameters.

Dialog Options - Tables

Table Tools

Transformers with table-style parameters have additional tools for populating and manipulating values.

Row Reordering

Enabled once you have clicked on a row item. Choices include:

Add a row
Remove a row
Move current row up one
Move current row down one
Move current row to top
Move current row to bottom

Cut, Copy, and Paste

Enabled once you have clicked on a row item. Choices include:

Cut a row - delete and copy to clipboard
Copy a row to the clipboard
Paste a row from the clipboard

Cut, copy, and paste may be used within a transformer, or between transformers.

Filter

Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output.

Import

Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers.

Reset/Refresh

Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers.

Note: Not all tools are available in all transformers.

Project ID	Available when the credential source is Embedded. The Google Cloud project ID.
Client Private Key	Available when the credential source is Embedded. Private key for device authentication. This can be generated with the instructions at https://cloud.google.com/iot/docs/how-tos/credentials/keys#generating_an_rsa_key.

Processing Behavior	Feature-Based
Feature Holding	No
Dependencies
Aliases
History	Released FME 2019.0

GoogleIoTConnector

Typical Uses

Configuration

Input Ports

Output Ports

Parameters

Editing Transformer Parameters

Reference

FME Community