Configure an alarm if no communication from sensor in past x minutes

[bpair]

Typically my sensors send updates every 4 minutes and if nothing changes every 10 minutes. With several sensors on a node this results in usually the node communicating withe gateway/controller every minute. If the controller does not receive any messages from a node after 15 minutes I would like to send an SMS message - "Communication lost with Node 123 - possible power failure". Only 1 message should be sent no matter how long the communication failure lasts. After the node establishes communication again I would like to send an SMS - "Communication with Node 123 has been restored."

How would you suggest accomplishing this? Do you have the concept of a node being "online" or "offline"? Could the timers be used?

[jkandasa]

@bpair This support available from 0.0.3-Alpah2 version (will be released soon).
In node table you can see Status(Up/Down) and Last seen (ex: 3 minutes ago)
We can achieve this requirement in two ways.

1. Configure Rule+Send SMS Operation.
   • Change Nodes alive check interval to 15 minutes. Default is 30 minutes. Available at Settings->System->MyController.
   • Configure 2 Send SMS operations. first one to send failure second one to send restored message
   • Create 2 rules.
     First one to trigger failure [Condition type: State, Node, Node name, == Down, Dampening: None. Select operation #1].
     Second one to trigger restored [Condition type: State, Node, Node name, == Up, Dampening: None. Select operation #2].
     In both the cases Ignore duplicate should be checked to avoid multiple messages.
2. Via the script
   • Create Rule with script condition or Timer with script operation
   • You can write your own script to check node status, you can use Last seen to get more accurate
     Scripting is not documented well. I will update the documents along with 0.0.3-Alpha2 release

[bpair]

Those sound like good options. I think the "last seen" is really useful on bot the node and sensor. I would only want to send notification for specific sensors or nodes and ideally the timing could be configurable, e.g. sensor x: 15 minutes, sensor b: 60 minutes.

Probably the custom script that runs every couple of minutes and checks the last seen is the most flexible approach.