Last Will

This tab allows to define what the broker shall send if the driver loses connection. Other clients can subscribe to the Last-Will topic if they want to detect if the MQTT driver lost connection to the broker. Note that the Last-Will is not sent if the MQTT driver orderly disconnects.

Figure 1. Last will tab

Topic

Topic which shall receive the Last Will message.

Message

The Last Will message which is sent to the defined topic on connection loss.

QoS

Quality of Service level for the Last Will message (refer to Details on the MQTT driver for further information on QoS levels).

  • 0: At most once
  • 1: At least once
  • 2: Exactly once

    For more information on Quality of Service, see Quality of Service.

Retain

Defines if the Last Will message shall be kept by the broker. If there is a new subscriber to this topic, the subscriber receives the retained message immediately. For more information on Retain, see Retain.