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.

If you are in "02 – Online automatic control mode with external temperature reading" mode the Vicki will use an external temperature reading. This will affect it Open window detection capabilities. It will still use its internal readings to determine whether or not the window has been opened, not the external temperature measurement.

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

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: 10min.
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.
		Default: 258 steps.
4	3:0	X – temperature difference to detect open window (in Celsius degrees). Default: 1 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