Keep-alive

Keep-alive command explanation

Periodically sent message which contains the most important device data.

For this device, the default keep-alive period is 240 minutes.

The data is described in Table 3. In Table 4 example packet is given.

Payload index	Value, [hex]	Bit index	Meaning
0	01	-	Command byte for this packet.
1	XX	-	Device battery voltage.$Voltage , [mV right ] = XX ∗ 8 + 1600$
2	XX	Bits 7:3	Reserved.
		Bit 2	Thermistor operational status: 1: Thermistor connection is broken; 0: The thermistor is properly connected.
		Bits 1:0	Thermistor temperature data, bits [9:8] - T[9:8]
3	XX	-	Thermistor temperature data, bits [7:0] - T[7:0]. The measurement resolution is 0.1.$℃$ $t , [° C ] = \frac{T [9 : 0]} {10}$
4	XX	-	Button press event data.

Table 3

Payload index	Value, [hex]	Bit index	Meaning
0	01	-	Command byte for this packet.
1	AB	-	Device battery voltage.$Voltage , [mV] = 171 ∗ 8 + 1600 = 2968$
2	02	Bits 7:3	Reserved.
		Bit 2	Thermistor operational status: 0: The thermistor is properly connected.
		Bits 1:0	Thermistor temperature data, bits 9:8 - T[9:8]
3	9B	-	Thermistor temperature data, bits 7:0 - T[7:0]. The measurement resolution is 0.1.$℃$ $t , [° C ] = \frac{0x29B} {10} = \frac{667} {10} = 66.7$
4	03	-	Button event data = 3 (three) button presses.

Table 4

Set keep-alive period command explanation

Sets the period of the device keep-alive command messages. See table 5 for details.

Byte index	Hex value – Meaning
0	02 – The command will set the device keep-alive period.
1	XX – keep-alive period in minutes. Value 00 isn’t applicable. Default value: 240 min.

Table 5

Example command, [Hex]: 020A

The example sets the keep-alive period to 10 minutes.

Note that the keep-alive period must respect the LoRaWAN messages duty cycle limitations. Otherwise the message will be sent when this is allowed.

Get keep-alive period command explanation

This command is used to get the device keep-alive command messages period. Server sends the command code and the response is sent from the device together with next keep-alive command. The sent command request and the received command response are described in Table 6. The keep-alive in the response is omitted for clarity.

Byte index	Sent request, [hex]	Received response, [hex]
0	12 – The command code.	12 – The command code.
1		XX – device keep-alive period in minutes.

Table 6

Example command sent from server, [HEX]: 12;

Example command response, [HEX]: 120А – Device keep-alive period is 10 minutes.