[SOLVED] Comparing 2 item states within a rule leads to error

Setup, Configuration and Use Scripts & Rules
1

Hi guys,

I’ve just got a quick question for a rule. I’d like to compare two temperatures to select the higher one. One temperature comes from a sensor that’s read by a binding, the other one is from the weather binding.

when Item KM200_Sensor_Aussentemp changed then
var Number VAR_KM200_Sensor_Aussentemp = KM200_Sensor_Aussentemp.state as DecimalType
var Number VAR_WEATHER_OWM_Home_Temperatur = WEATHER_OWM_Home_Temperatur.state as DecimalType

the above stated code leads to an error - can you please tell me what I’m doing wrong?;

'state' is not a member of 'org.eclipse.smarthome.core.library.types.DecimalType'; line 37, column 94, length 20

Thanks in advance an BR,
Christian

2

What do you have on line 37 of your rule file?

3

Can you please paste full rule, or at least a stripped down version that reproduces your issue?

4

Hi @5iver, Hi @diyha!

Many thanks for your fast replies, gentlemen. Meanwhile I figured it out; I’m writing the “output” of the logical substeps into a logfile and this was the line of code that caused an error, because I used VARIABLE.state here (copy+paste is not always your friend).

And as .state is only for Items that was causing the error.

rule "Höhere Außentemperatur wählen"
	when Item KM200_Sensor_Aussentemp changed then
		var Number VAR_KM200_Sensor_Aussentemp = KM200_Sensor_Aussentemp.state as DecimalType
		var Number VAR_WEATHER_OWM_Home_Temperatur = WEATHER_OWM_Home_Temperatur.state as DecimalType		

		if (VAR_KM200_Sensor_Aussentemp > VAR_WEATHER_OWM_Home_Temperatur)
		{
			VAR_temperatur = VAR_KM200_Sensor_Aussentemp
		}
		else if (VAR_WEATHER_OWM_Home_Temperatur > VAR_KM200_Sensor_Aussentemp)
		{
			VAR_temperatur = VAR_WEATHER_OWM_Home_Temperatur
		}
	end

Is there a possibility to write a rule-trigger that fires when VAR_temperatur is changed or do I have to do a postUpdate on an “virtual” item?

Thanks & BR,
Christian

5

Maybe you need to convert the state into Number as:

var Number VAR_KM200_Sensor_Aussentemp = KM200_Sensor_Aussentemp.state as Number
var Number VAR_WEATHER_OWM_Home_Temperatur = WEATHER_OWM_Home_Temperatur.state as Number
6

Nope. As the variable is derived from two Items, it might do whatever it is you want by triggering a rule from change of either of those.

7

Hi guys! Thank you very much for your help. I marked that topic as solved!

Here we go, plain and simple:

rule "Höhere Außentemperatur wählen"
	when Item KM200_Sensor_Aussentemp changed then
		var Number VAR_KM200_Sensor_Aussentemp = KM200_Sensor_Aussentemp.state as DecimalType
		var Number VAR_WEATHER_OWM_Home_Temperatur = WEATHER_OWM_Home_Temperatur.state as DecimalType		

		if (VAR_KM200_Sensor_Aussentemp > VAR_WEATHER_OWM_Home_Temperatur)
		{
			VAR_temperatur = VAR_KM200_Sensor_Aussentemp
		}
		else if (VAR_WEATHER_OWM_Home_Temperatur > VAR_KM200_Sensor_Aussentemp)
		{
			VAR_temperatur = VAR_WEATHER_OWM_Home_Temperatur
		}

		//sendTelegram("CSIhub", "[WEATHER/DEBUG]\r\n> Sensor-Temp geändert.\r\nVAR_temperatur = " + VAR_temperatur.toString)
	end
8

As your value is derived from two Items, you could improve the rule to trigger if either of those Items changes

rule "Höhere Außentemperatur wählen"
when
    Item KM200_Sensor_Aussentemp changed or
    Item WEATHER_OWM_Home_Temperatur changed
then
    ...
9

TY very much, @rossko57 - added your snippet to my rule!