I tried to set a counter to the sensor register #8 witch is for the SCS with ID 1. Then I added a temperature box on the screen and set the counter number 5. I'm a little confused what application number should it be. I couldn't find in kt manual too.
I dont know what you mean by application number
To display temperature in degrees C on the KT03, create a Value Element
This is a button that displays a number 0 to 255
In Status Properties, set Status Type = Sensor Register, and set Sensor Number to the sensor corresponding to the SCS that you have.
SCS ids 1 to 15 correspond to Sensors 8 to 23
Hence SCS 1 corresponds to Sensor Register 8
The number in the sensor registers is in degrees Fahrenheit because this is what is provided by the SCS temp sensor
To convert it to Celcius and display as such, go to Events > Sensor Responses, and assign a Response to convert F to C