How Ops3A Sensors Work
Ops3A sensors have a series of heartbeats (transmissions) and assessments (data queries) to determine the state it’s in, if it is time to send a transmission and what information to transmit. This article shows a simple temperature sensor going in and out of an aware state and what happens in each time period.
Sensors communicate with gateways through a series of incremental "heartbeats." These heartbeats periodically return data from the sensor indicating the current reading. If the reading is below a set aware state interval, the sensor data will fall into a "Non-aware" classification. If the reading is above the desired setting, then it will enter an "Aware" state and immediately notify the desired users.
An example of a temperature sensor reporting to the gateway in two-hour heartbeats follows. 120 minutes is the default setting for heartbeats on the Ops3A Platform.
Example:
- Heartbeat Interval: 120 Minutes
- Aware State Heartbeat: 120 Minutes
- Assessments per Heartbeat: 3
- Max temperature threshold: 257°F
Assuming that these are the temperature settings for the "Sensor Reading Event," the data returned might look like this:
1:00 PM -> Sensor transmits current temperature of 38°F; temperature is under the threshold (Non-aware)
a. The sensor sets the timer for the next assessment for 120 minutes.
3:00 PM -> Sensor assesses temperature of 200°F; temperature is still under the threshold (Non-aware)
a. Sensor resets the timer for the next assessment 120 minutes
As you can see from the above examples the temperature readings are below 257°F so the sensor has not entered an Aware State. Now let's see what happens when it does enter this state:
5:00 PM -> Sensor assesses temperature of 258°F; temperature is over the threshold (Aware)
a. Sensor enters Aware Mode,
b. Transmits current temperature of 258°F,
c. Sets timer for Aware State Assessment, 3 minutes 20 seconds.
7:00 PM -> Sensor assesses temperature of 258°F; temperature is still over the threshold (Aware)
a. Sensor resets the timer for the next assessment, 3 minutes 20 seconds
9:00 PM -> Sensor assesses temperature of 200°F; temperature is under the threshold (Non-aware)
a. Sensor leaves Aware Mode and resets heartbeat to 30 minutes non-aware heartbeat interval b. Transmits a current temperature of 200°F.
c. Sensor sets a timer for the next assessment 120 minutes
We can now see that the temperature is decreasing the ambient environment is returning to normal. The next reading delivered two hours later will confirm this.
11:00 PM -> Sensor assesses temperature of 50°F; temperature is under the threshold (Non-Aware)
a. Sensor resets the timer for the next assessment 120 minutes