External temperature measurement

1. Automatic temperature control mode with external temperature reading

When enabling this mode you need to first set the External temperature sensor value with the 3B or 3C command below. If you don't the FCT will assume a target temperature of 0°C degrees and act accordingly.

For example send the following command set (whichever of the two you use will have the same end result):

Temperature with accuracy of 1°C

0x3B183501 (set external temperature to 24°C)

or

Temperature with accuracy of 0.1°C

0x3C00F03501 (set external temperature to 24.0°C)

This will set the target temperature to a nice 24°C and activate the External temperature mode and await a new reading.

SET

This command activates/deactivates the automatic temp. control mode with external temp. reading.

Byte index	Hex value – Meaning
0	35 – The command code.
1	00: Deactivate the automatic temp. control mode; Default value. 01: Activate the automatic temp. control mode.

Example downlink: 0x3501 – Activate the automatic temp. control mode with external temp. reading.

GET

This command gets whether automatic temp. control mode with external temp. reading is enabled or disabled?

Byte index	Sent request	Received response
0	36 – Command code	36 – Command code
1		00: The automatic temp. control mode is deactivated. 01: The automatic temp. control mode is activated.

Example downlink sent by the server: 0x36;

Example command response: 0x3601 – The automatic temp. control mode with external temp. reading is activated.

2. External temperature sensor value

The server sends this command to Fan Coil Thermostat device when it has a new measured temperature by the external sensor. This external temperature will be used by Fan Coil Thermostat for the internal temperature control algorithm. The commands are detailed in the tables below.

2.1 Set еxternal temperature sensor value with resolution 1.0°C

Byte index	Hex value - Meaning
0	3B – The command code.
1	XX – The ext. temperature in degrees Celsius. The value must be greater than 0°C!

Example downlink: 0x3B14 – the server notifies Fan Coil Thermostat that the measured temperature by the external sensor is 0x14[HEX] => 20[DEC] = 20°C.

The allowed range is 1...99°C (1.0°C resolution).

2.2 Set/Get еxternal temperature sensor value with resolution 0.1°C

SET

You can set the external temperature with the command:

Byte index	Hex value – Meaning
0	3C – The command code.
1	XX - T[15:8].
2	XX - T[7:0].

T[15:0] = Texternal[°C] * 10; The value of Texternal[°C] must be greater than 0°C!

Example command: 0x3C0102 - the server notifies the Fan Coil Thermostat that the measured temperature by the external sensor is 25.8°C => 25.8 * 10 = 258 [DEC] => 0x0102 [HEX];

GET

When the Fan Coil Thermostat is in "Automatic temperature control mode with external temperature reading", the command is sent together with the keepalive of the device.

Byte index	Sent request	Received response
0	3E – Command code	3E – Command code.
1		XX - T[15:8].
2		XX - T[7:0].

Texternal[°C] = T[15:0] / 10;

Example command: 0x3E;

Example response: 0x3E0102;

0x0102 [HEX] = 258 [DEC] => Texternal = 258 / 10 = 25,8°C.

The allowed range is 0.1...99.9°C (0.1°C resolution).