Device Connectivity Status

• Feature Overview
• Next steps

Feature Overview

NDU Device State service is responsible for monitoring of the device connectivity state and triggering device connectivity events that are pushed to the Rule Engine As a platform user, you are able to define how to react on this events.

Supported events are:

• Connect event - triggered when device connects to NDU. Meaningful in case of session based transports like MQTT. Will be also triggered for HTTP transport, but in this case it will be triggered on each HTTP request;
• Disconnect event - triggered when device disconnects from NDU. Meaningful in case of session based transports like MQTT. Will be also triggered for HTTP transport, but in this case it will be triggered on each HTTP request;
• Activity event - triggered when device pushes telemetry, attribute update or rpc command;
• Inactivity event - triggered when device was inactive for a certain period of time. Please note that this event may be triggered even without disconnect event from device. Typically means that there was no activity events triggered for a while;

Device State service is responsible for maintaining the following server-side attributes:

• active - represents current device state, either true or false;
• lastConnectTime - represents last time device connected to NDU, number of milliseconds since January 1, 1970, 00:00:00 GMT
• lastDisconnectTime - represents last time device disconnected from NDU, number of milliseconds since January 1, 1970, 00:00:00 GMT
• lastActivityTime - represents last time device pushed telemetry, attribute update or rpc command, number of milliseconds since January 1, 1970, 00:00:00 GMT
• inactivityAlarmTime - represents last time inactivity event triggered, number of milliseconds since January 1, 1970, 00:00:00 GMT <!– ## Configuration

Device State service uses global configuration parameter for inactivity timeout. This parameter is defined in thingsboard.yml (state.defaultInactivityTimeoutInSec) and by default it is set to 10 seconds. User can overwrite this parameter for individual device by setting “inactivityTimeout” server side attribute (value is set in milliseconds).

Device State service uses global configuration parameter to detect inactivity events. This parameter is defined in thingsboard.yml (state.defaultStateCheckIntervalInSec) and by default it is set to 10 seconds.

Next steps

• Getting started guides - These guides provide quick overview of main NDU features. Designed to be completed in 15-30 minutes.

• Installation guides - Learn how to setup NDU on various available operating systems.

• Connect your device - Learn how to connect devices based on your connectivity technology or solution.

• Data visualization - These guides contain instructions how to configure complex NDU dashboards.

• Data processing & actions - Learn how to use NDU Rule Engine.

• IoT Data analytics - Learn how to use rule engine to perform basic analytics tasks.

• Hardware samples - Learn how to connect various hardware platforms to NDU.

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