Trigger does not fire

[SpeedyGo]

Hello friends,
I am still quite new to Zabbix and have been trying to complete a simple task for days now, but it won't work:
An item returns a value of type integer. A trigger should fire if this value does not change over a certain period of time.
The value of the item does not currently change!
This trigger does not fire:
changecount(Host/Key[RegistryQuery],10m)=0
According to the documentation, this trigger should fire after ten minutes if the value of the item has not changed.
It does not work with this trigger either:
countunique(Host/Key[RegistryQuery],3m)<1 (or =0)

So I used the DISCARD function in the item to specify that values are no longer written to the DB if they are equal to the previous value and then used this trigger:
nodata(Host/Key[RegistryQuery],3m)=1
But although no more values are written, this trigger does not fire either.

What am I doing wrong?

[SpeedyGo]

Hello friends,
now it runs! The only working thing in my case is the NODATA trigger. My mistake was only a wron syntax:
nodata(Host/Key[RegistryQuery],3m)=1
should be:
nodata(Host/Key[RegistryQuery],3m)<>0

that's it!

[cyber]

How often do you check for values?
Trigger gets recalculated each time, when new value is received.

nodata trigger should still work...

[SpeedyGo]

Hello Cyber,

Thank you for your answer!

For test purposes, the item provides a value per minute. I want to get a trigger after a short time.
The ZABBIX description: countunique(/host/key,10m) #the number of unique values for the last 10 minutes until now
is clear. No matter how many item values arrive, if they are always the same after ten minutes, the trigger should fire.

Then I just tried this with the nodata function. I added a DISCARD UNCHANGED to the item in preprocessing. No more values were returned. The nodata trigger did not fire.

Now I have tried it with MIN / MAX. This trigger triggers at some point but unfortunately not after the set 3 minutes.

min(Host/Key[RegistryQuery],3m)= max(Host/Key[RegistryQuery],3m)

[SpeedyGo]

Hello friends,
now it runs! The only working thing in my case is the NODATA trigger. My mistake was only a wron syntax:
nodata(Host/Key[RegistryQuery],3m)=1
should be:
nodata(Host/Key[RegistryQuery],3m)<>0

that's it!