how to configure a rule to send an email for boolean telemtry change

Question

Hello,

I want to configure a rule to send an email when telemetry value changes, the telemetry property schema is boolean.

when using a condition with integer value the rule works fine, but for the boolean i can't trigger the rule.

when a rule is configured will it trigger every time a telemetry message arrives with the correct conditions or only once after it enters the condition?

Answer 1

Hello Avigdor,

welcome to this moderated Azure community forum.

I noticed you are interested in sending an email on changes of data.

I created something like that using Azure Stream Analytics in Azure. Check the blog post.

This is not part of Azure IoT Central.

Azure IoT Central is capable of forwarding incoming messages to Azure resources:

Via an eventhub, you can forward data to this stream analytics job.

As an alternative, you can also look at using Azure Data Explorer and use Azure monitoring to raise alerts based on Azure Data Explorer queries.

So you need to extend your Azure IoT Central solution to get to this data.

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Answer 2

I have a rule with a single condition that checks if a Boolean telemetry value is true. This rule triggers every time the telemetry value is true - this is the standard behavior for rules.

You may be able to use the time aggregation - with Boolean values you can count how many times the value is true within a specified time window. However, I think you need to set the aggregate count value in a cloud property on the device. In the screenshot, "Threshold" is a cloud property: