Keep-alive
Keep-alive explanation
The Keep-alive is a periodically sent message which contains the most important device data.
T-Valve has two types of keep-alive packets, depending on the payload length, a Short and a Long one.
Packet payload size [Bytes]
Description
Short [2]
Long [5]
Full device data. Such a packet is send from the device on certain events or by server request with command 0x08 or once per day
Short payload
Byte index
Bit index
Hex value - Meaning
0
[7:0]
Temperature measured by sensor 1. This sensor measures the water temperature, thus only positive values are expected. The resolution is 0.5°C. The temperature is calculated by the expression: T, [°C] = (Bits[7:0])/2
1
7
Valve state, the values are in BIN format: 0 - The valve is closed – water isn’t flowing 1 - The valve is open – water is flowing.
1
[6:0]
Temperature measured by sensor 2. This sensor measures the ambient temperature. The measurement range is (-10°C to 50°C) and the resolution is 0.5°C. The temperature is calculated by the expression: T, [°C] = ((Bits[6:0])-20)/2 Examples: T = (20 - 20) / 2 = 0°C T = (120 - 20) / 2 = 50°C T = (0 - 20) / 2 = -10°C T = (75 - 20) / 2 = 27.5°C
Example packet: 0x0044
00[HEX] = 0[DEC] -> T, [°C] = 0/2 = 0°C
The water temperature is 0°C
44[HEX] = 01000100[BIN] -> [7] = 0 -> Valve is open [6:0] = 01000100-> T, [°C] = (68-20)/2 = 24°C
Long Payload
Byte index
Bit index
Hex value - Meaning
0
[7:5]
Reason to send the packet, the values are in BIN format: 000 - Requested by server command 0x08 or one day elapsed 001 - Device test switches combination is pressed 010 - Flood detected by device sensor 011: - “Open” or “Close” push-button is pressed 100 - Fraud detected – box tamper switch or magnetic sensor
0
4
Reserved
0
3
Box tamper status, the values are in BIN format: 0 - No box tamper detected 1 - Box tamper detected
0
2
Flood detector wire status, the values are in BIN format: 0 - The wire is working 1 - Wire is not working
0
1
Flood detection status, the values are in BIN format: 0 - No flood detected 1 - Flood detected
0
0
Magnet detection status, the values are in BIN format: 0 - No magnet presence is detected 1 - Magnet presence is detected
1
7
Alarm validation indicator. This bit is set to 1 when the user presses the “Verify” button when leakage alarm is active. After, on any response from the application server that bit is cleared
1
6
Manual valve open indicator, the values are in BIN format: 0 - Manual opening of the valve is disabled 1 - Manual opening of the valve is enabled
1
5
Manual valve close indicator, the values are in BIN format: 0 - Manual closing of the valve is disabled 1 - Manual closing of the valve is enabled
1
[4:0]
Device software version
2
[7:0]
In reduced access mode controls the valve close time. The resolution is in minutes
3
[7:0]
In reduced access mode controls the valve open time. The resolution is in minutes
4
[7:0]
Battery voltage. It is calculated by the formula: Battery voltage, [mV] = (Bits[7:0])*8 + 1600
Example packet: 0х64620000A4
64620000A4[HEX] = 0110 0100 0110 0010 0000 0000 0000 0000 1010 0100[BIN]
Byte 0: [7:5] = 011 -> Reason for packet “Open” or “Close” push-button is pressed [3] = 0 -> No box tamper detected [2] = 1 -> Wire is not working [1] = 0 -> No flood detected [0] = 0 -> No magnet presence is detected
Byte 1: [7] = 0 -> Alarm not verified [6] = 1 -> Manual open enabled [5] = 1 -> Manual close enabled [4:0] = 00010 -> Firmware version 2
Byte 2: [7:0] = 0000 0000 -> Close time 0 minutes
Byte 3: [7:0] = 0000 0000 -> Open time 0 minutes
Byte 4: [7:0] = 1010 0100 -> Battery voltage, [mV] = 164*8 + 1600 = 2912mV
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