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

Question

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

Avigdor 40

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? User's image

Manas Mohanty 17,185 Reputation points Microsoft External Staff Moderator

2025-02-26T08:08:33.25+00:00

Hi Avigdor

We are checking to see if the pointers from Dom on using Parameter counting True or False over a certain time window as threshold worked for you.

Thank you.
Manas Mohanty 17,185 Reputation points Microsoft External Staff Moderator

2025-02-27T12:28:53.79+00:00

Hi Avigdor

Hope the pointers shared from Sander van de Velde | MVP helped addressed your issue.

Thank you.
Manas Mohanty 17,185 Reputation points Microsoft External Staff Moderator

2025-02-28T12:47:59.3866667+00:00

Hi Avigdor

We have not heard from you. Hope the pointers shared addressed your query.

Thank you.

Answer accepted by question author

Sander van de Velde | MVP 37,066 MVP

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:

User's image

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.

If the response helped, do "Accept Answer". If it doesn't work, please let us know the progress. All community members with similar issues will benefit by doing so. Your contribution is highly appreciated.

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Manas Mohanty 17,185 Reputation points Microsoft External Staff Moderator

2025-02-26T08:08:33.25+00:00

Hi Avigdor

We are checking to see if the pointers from Dom on using Parameter counting True or False over a certain time window as threshold worked for you.

Thank you.
Manas Mohanty 17,185 Reputation points Microsoft External Staff Moderator

2025-02-27T12:28:53.79+00:00

Hi Avigdor

Hope the pointers shared from Sander van de Velde | MVP helped addressed your issue.

Thank you.
Manas Mohanty 17,185 Reputation points Microsoft External Staff Moderator

2025-02-28T12:47:59.3866667+00:00

Hi Avigdor

We have not heard from you. Hope the pointers shared addressed your query.

Thank you.

Answer 1

Dominic 1,706 Microsoft Employee

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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:

Avigdor 40 Reputation points

2025-02-26T08:28:03.2266667+00:00

Thanks Dom,

I'm looking for something a bit different, I want to send a notification for every transition of the value, from 0 to 1 and from 1 to 0 and only when there is transition. if the value is sent from the device with no change I don't need a notification.
Is it possible to create such a rule?
Dominic 1,706 Reputation points Microsoft Employee

2025-02-26T10:49:08.0833333+00:00
This isn't a scenario that IoT Central rules support. I think your options are:

Look at Sander van de Velde's approach - you can use IoT Central's continuous data export capability to forward telemetry to another cloud service that can detect changes in a Boolean value.

Another approach would be to continue to use an IoT Central rule - but have the rule invoke a stateful Azure Function - you could create a stateful function that watches for changes in a Boolean and sends an email. Stateful functions are called durable functions: https://learn.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-overview. (Stateful Logic Apps is another option)

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

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