calculated item not supported

[Alex_n]

Hello!,
I'm starting to understand the zabbix, please help with the problem:

I want to detect-notify when the difference between events 0 is a few minutes
For this, I made a template

1. 2 item
   1. get value (float) from script - run every 5s
   2. by key(from step1) get change() - run every 5s
2. trigger view item with diff and wait 10 minutes - key_with_diff.min(10m) and notify

I see this message in logs, gui

12425:20200430:155612.989 item "HOST:key.diff.[param1, param2]" became not supported: Cannot evaluate expression: "Cannot evaluate function "prev()": item "HOST:script.py[param1, param2]" not supported.".

I setup 155 items with prototypes (and now 7 items with this problem)
If press button "check now" error dissaperar

time script with receive data ~0.3c

I don't know where the problem.
Maybe that is executed at 1 time? I tried to change it
also tried using instead of change() - avg() - the same situation


Thanks for any help

[Alex_n]

fixed

• delete 2-nd item (calculate diff)
• change trigger with use delta function - key.delta(10m) = 0