# Alarming in ignition

**URL:** <https://forum.inductiveautomation.com/t/alarming-in-ignition/26431>\
**Category:** Ignition\
**Created:** [July 10, 2019, 11:54am UTC](https://forum.inductiveautomation.com/t/alarming-in-ignition/26431 "2019-07-10T11:54:19Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![annr](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@annr](https://forum.inductiveautomation.com/u/annr)\
**Post date:** [July 10, 2019, 11:54am UTC](https://forum.inductiveautomation.com/t/alarming-in-ignition/26431/1 "2019-07-10T11:54:19Z")

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I have four edge gateways sending data via mqtt to a central ignition gateway.If communication from any of the edge gateways goes down then i would like to get an alarm regarding which edge gateway has communication problems.  
So far i have created an expression tag for alarming with the following configured under “Expression” :  
dateDiff({[MQTT Engine]Edge Nodes/Skid001/001\_1M\_System\_Pulse.LastChange}, now(), “sec”) \>= 120 || {[MQTT Engine]Engine Info/Edge Nodes/NodesOffline} = 1

“1M\_System\_Pulse” is a tag that alternates between on and off every 1 minute.  
The problem with this is that if any of the nodes goes offline i will get an alarm but it will be difficult to detect which particular edge gateway has the problem with communication.Ideally i would like to get an  
alarm that tells me which particular edge gateway has the problem.

Any help would be appreciated.