The software supports so-called Birth and Last Will and Testament (LWT) messages. The former is used to send a message after the service has started, and the latter is used to notify other clients about an ungracefully disconnected client. In addtion to a Birth message on startup the Birth message is also published cyclic as a harbeat.
Birth message:
Topic: Devices/WAGO-PFC200/availability
Payload: online
LWT message:
Topic: Devices/WAGO-PFC200/availability
Payload: offline
Note that the Topics and payloads can be changed in de code. The Birth message is by default published during startup and after that every 5 seconds (hartbeat). This can be changed as well in the code.