Dead sensor detection

A precondition for effective monitoring is to ensure that sensor data is actually received. The sensor data is obtained via connectors that can pull data via REST or process MQTT push messages. If for some reason the connection fails the current state is not updated and monitoring will not be correct. Every time a topic value is updated the time and location of the topic are updated as well. This information can be used to check when data was updated last.

Assert updated

The Asset updated block has one input for the name of the topic and one input for a date and time. Instead of using a fixed date you can use the running date control found in the Variables section. For example, to check the update time of all weather topics you can drag a loop block with variable topic and pass the topic to the Assert updated block. The time control specifies the maximum age of the topic state, in this case 3 hours.

Wildcards

Using a loop to iterate over topics makes it possible to add If statements. You can for instance add a conditional statement in the loop that checks if the name of the topic includes something like server and based on that specify a diffent value that with a topic that includes notebook. If all topics need to comply to the same value you can use a wildcard.