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How do I trigger something when the first error appears, and the last error is resolved?



I want to trigger a "warning" light by http request when there is an error status. this works for "mirroring" the state of one sensor: When the error state appears, I notify a smart lightswitch per HTTP request, a light goes on. If the sensor leaves error state, I trigger another http request, and the light goes off. All good for one sensor.

But how do I do this when I want to signal that in a group of sensors none is in error state? If e.g. I trigger the off state of the light on resolving one sensor error, there might still be another, unrelated one that should keep the light on.

Is there some sort of notify on "one of a group of sensors has an alert, notify" and "the last error in the group was resolved, notify"?

http iot notification prtg signal-light

Created on Jun 23, 2022 11:22:23 AM

1 Reply



Hello Ralph,

Thank you for your message.

Regarding what you would like to achieve, it is not possible to define notification triggers based on a group (they only apply on sensors). Nevertheless, you have the possibility to trigger the notification when all sensors are back in UP state by using the Business Process sensor.

Within the Settings of the sensor, you need to give a name to the channel, define the threshold for warning and error state as well as select the group you desire to get the status from.

Here is an example below: Business Process sensor

The sensor will then automatically check the number of UP sensors, compare the result with the thresholds you defined and return the corresponding status (UP, Warning, Down).

When you have done that, you need to delete the existing trigger and create it again for this sensor only. You should get the behavior you expect afterwards.

If you have questions, do not hesitate.


Created on Jun 28, 2022 8:30:47 AM by  Florian Lesage [Paessler Support]

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