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,[mVright]=XX8+1600Voltage , [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]=T[9:0]10t , [° 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]=1718+1600=2968Voltage , [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]=0x29B10=66710=66.7t , [° 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.

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