This article will illustrate how the Notify After Aware Period notification works and our recommended set up.
How Does the “Notify After Aware Period” Notification Works?
When the server receives a message from the sensor, it looks for notifications assigned to the sensor. If the server determines there is an active “Notify After Aware Period” notification, it takes the current data just sent to it and checks it against the parameters of the notification. At that time the server calculates, based on current message received, if the sensor is in aware state. Next, it compares previous messages to determine how long the sensor has been in the aware state. If it has been aware for more than the time set to “Alert After” then the notification is sent.
Aware messages trigger communication at the gateway while standard (Non Aware) messages do not. The server knows within a couple of seconds that the sensor has delivered an aware message but if the sensor has returned to a normal state the message doesn’t get delivered until the regular heartbeat. Because the message is a non-aware message, it gets queued on the gateway and doesn’t get delivered right away. Due to this the server doesn’t know if the sensor is still in aware mode or not. It has to wait for the next message from the sensor to know that it is still in aware mode.
We recommend having the Notify After timer set just shorter than the Aware State Heartbeat so that when the second message comes in the timer has already elapsed.
A few examples:
Aware state heartbeat: 30 min
Notify after timer: 29 min
1:00PM Sensor enters aware mode and transmits the first aware reading.
1:30PM Sensor is still in the aware mode and sends the second aware reading. Server receives this message and compares to determine that the sensor has been aware for 30 min which is longer than 29 so the notification is sent. (At 1:30 after 30 min of aware state)
Aware state heartbeat: 60 min
Notify after timer: 30 min
1:00PM Sensor enters aware mode and transmits the first aware reading.
2:00PM Sensor is still in the aware mode and sends the second aware reading. Server receives this message and compares to determine that the sensor has been aware for 60 min which is longer than 30 so the notification is sent. (At 2:00 after 60 min of aware state)
Aware state heartbeat: 30 min
Notify after timer: 31 min
1:00PM Sensor enters aware mode and transmits the first aware reading.
1:30PM Sensor is still in the aware mode and sends the second aware reading. Server receives this message and compares to determine that the sensor has been aware for 30 min which is shorter than 31 so the notification is NOT sent.
2:00PM Sensor is still in the aware mode and sends the second aware reading. Server receives this message and compares to determine that the sensor has been aware for 60 min which is longer than 31 so the notification is sent. (At 2:00 after 60 min of aware state)
Aware state heartbeat: 15 min
Notify after timer: 29 min
1:00PM Sensor enters aware mode and transmits the first aware reading.
1:15PM Sensor is still in the aware mode and sends the second aware reading. Server receives this message and compares to determine that the sensor has been aware for 15 min which is shorter than 29 so the notification is NOT sent.
1:30PM Sensor is still in the aware mode and sends the second aware reading. Server receives this message and compares to determine that the sensor has been aware for 30 min which is longer than 29 so the notification is sent. (At 1:30 after 30 min of aware state)