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The heartbeat message uses port 2 and it is always confirmed. The heartbeat message is sent every 24 hours (by default).
Byte | Bits | Name |
|---|---|---|
0 | 04..40 | Error Mask |
7..5 | Reserved | |
1 | 7..0 | Battery voltage - the last value |
2 | 7Reserved..0 | Battery voltage - the mean value(last 24 hours) |
Heartbeat messages allow the device’s health monitoring using Error Mask, where all zeros values which are not hardware issues were detected.
Heartbeat messages are also used to initiate the re-join procedure (which is similar to the join procedure). If a count of sequential heartbeat messages without acknowledgment is bigger than the Heartbeat NACK limit (described in 4.2.5) re-join procedure will be initiated. This behavior assumes that the connection with the network has been lost. This is generally a good indicator that the Gateways are not able to maintain stable communication with the sensor.
To convert transmitted values of battery voltage to mV, use the following formula:
Vbat = (2400+value*5)mV,
where value is Battery voltage value transmitted in the message.
4.2.3 Startup
The startup message uses port 3 and it is always confirmed. It will be sent after every startup/reboot /(re-)join event:
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