Open window detection

The open window detection function works by looking for a sudden drop in temperature.

The detection algorithm takes readings every 1 minute, if the temperature dropped more than the threshold value, the valve is closed.

Therefore, it's not 100% reliable and can be affected by outdoor temperature, position of the device on the radiator, position of the radiator in the room and more factors.

Open window commands with delta t 0.1 accuracy

These commands are only available for f.w. >= 4.2

For f.w. < 4.2, please use the command with accuracy 1.0 (described further below)

SET

Set open window detection parameters (0.1 accuracy)

To detect open window, the difference between the currently and previously measured temperatures must be equal or greater than a specified temperature difference. A new temperature value is obtained every minute.

Byte index	Bit index	Hex value - Meaning
0	-	45 – The command will set Vicki open window detection parameters.
1	7:1	Reserved.
1	0	1 – Enable the open window detection functionality. 0 – Disable (Default).
2	-	XX – Duration for the valve to stay closed after open window detection. Resolution – 5 minutes. Default duration is 10 minutes.
3	-	XX – Temperature difference to detect open window (in Celsius degrees), pre-multiplied by 10. Default is 1.0 Celsius. Minimum value is 0.2 Celsius

Example downlink: 0x4501060D

0x45 - Command code

0x01 - Enable open window detection

0x06[HEX] -> 06[DEC] x 5[resolution] = 30 minutes

0x0D[HEX] -> 13[DEC] / 10 = 1.3 degrees

The command will Enable the open window detection and set the valve to be closed for 30 minutes if a delta of 1.3°C is reached.

GET

Get open window detection parameters (0.1 accuracy)

This command is used to get Vicki open window detection parameters. Server sends the command code and the response is sent from Vicki together with the next keep-alive command.

Byte index	Sent request	Received response
0	46 – Command code.	46 – The command code.
1		Bits [7:1] - Reserved
1		Bit 8: Open window detection enable/disable bit 1: Open window functionality is enabled; 0: Open window functionality is disabled.
2		XX – duration for the valve to be at the desired position, after open window detection. Resolution – 5 minutes. Default value is 2, meaning 10 minutes.
3		XX - Temperature delta with resolution 0.1 Celsius degrees. Value is premultiplied by 10.

Example downlink sent by the server: 0x46;

Example command response: 0x4601020F - Enable the open-window detection, duration is 0x02 = 02*5 = 10 minutes, delta is 0x0F = 15/10 = 1.5 degrees Celsius

Open window commands with delta t 1.0 accuracy

SET

Set open window detection parameters (1.0 accuracy)

To detect open window, the difference between the currently and previously measured temperatures must be equal or greater than specified temperature difference. New temperature value is obtained every minute.

In firmware versions >= 3.5, Vicki is fully closing the valve, regardless of the motorPosition defined in bytes 3 and 4 below.

Byte index	Bit index	Hex value - Meaning
0	-	06 – The command will set Vicki open window detection parameters.
1	7:1	Reserved.
1	0	1 – Enable the open window detection functionality. 0 – Disable (Default).
2	-	XX – Duration for the valve to stay closed after open window detection. Resolution – 5 minutes. Default duration is 10 minutes.
3	-	XX – motor position to be set when open window detected, bits 7:0.
4	7:4	X – motor position to be set when open window detected, bits 11:8.
4	3:0	X – temperature difference to detect open window (in Celsius degrees). Default is 2 Celsius.

Example downlink 1: 0x0601041C23

0x06 - Command code

0x01 - Enable open window detection

0x04[HEX] -> 04[DEC] x 5[resolution] = 20 minutes

0x1C[HEX] -> 00011100[BIN]

0x23[HEX] -> 00100011[BIN]

0011[BIN] -> 03[DEC] = 3 degrees

001000011100[BIN] -> 540[DEC] = 540 steps

The command will Enable the open window detection and set the motor position to 450 steps for 20 minutes if a delta of 3°C is reached.

Example downlink 2: 0x0600041C23 – Disable open window detection.

GET

Get open window detection parameters (1.0 accuracy)

This command is used to get Vicki open window detection parameters. Server sends the command code and the response is sent from Vicki together with the next keep-alive command. The sent command request and the received command response are described in Table 20. The keep-alive in the response is omitted for clarity.

Byte index	Bit index	Sent request	Received response
0	-	13 – Command code.	13 – The command code.
1	7:1		Reserved;
1	0		Open window detection enable/disable bit: 1: Open window functionality is enabled; 0: Open window functionality is disabled.
2	-		XX – duration for the valve to be at the desired position, after open window detection. Resolution – 5 minutes.
3	-		XX – motor position to set when open window detected, bits 7:0.
4	7:4		X – motor position to set when open window detected, bits 11:8.
4	3:0		X – temperature difference to detect open window detection (In Celsius degrees).

Table 20

Example command sent from server: 0x13;

Example command response 1: 0x130102F412 – Open window detection functionality is enabled. When open window is detected, the motor will stay for 10 minutes on the specified position. Desired motor position is 500 steps. Open window will be detected when the temperature difference between the previously and currently measured temperatures become 2°C or greater.

Example command response 2: 0x130002F412 – Open window detection functionality is disabled.