Calculated field based on agent2 and mqtt

[mario.in.dcstar]

hello

we get the power from our shelly devices with mqtt and agent 2 but when i want to make a calculated field for the current (power/voltage), than I get an error on the key from mqtt field
name: current
key: "mqtt.get["192.168.0.10:1883","shellies/power/3402/emeter/1/power"]".

preprocessing: custom multiplier 0.1 (i know, just for this example)

error: Item with key "mqtt.get["192.168.0.10:1883","shellies/power/3402/emeter/1/power"]" already exists on "System-10.21-PreProd". ====> that is the power measurement

same concept with rest calls works

any ideas what i am doing wrong?

Mario

[mario.in.dcstar]

Hello cyber,


I messed up my explanantion, sorry!
Let me start again:

1. power meassurement (via mqtt on agent go)

type: Zabbix agent (active)
Key: mqtt.get["192.168.0.10:1883","shellies/power/3402/emeter/1/power"]
Type of info: Numeric (float)
units: W


2. current calculation

type: calculated
key: 3402current
formula: last(mqtt.get["192.168.0.10:1883","shellies/power/3402/emeter/1/power"])/220
==> last('key ref')/220
Type of info: Numeric (float)
units: A


ERROR: Invalid parameter "/1/params": incorrect calculated item formula starting from "last(mqtt.get["192.168.0.10:1883","shellies/power/3402/emeter/1/power"])/220".




The working version with rest calls:

1. power measurement (rest call)

type: http agent
Key: RSSI3405power
URL: http://192.168.0.167/status

preprocessing:
JSONPath: $.body.emeters[1].power


2. current calculation

type: calculated
Key: RSSI3405current
Formula: last("RSSI3405power")/last("RSSI3405voltage")


So if I am correct, the formula should contain the "Key" of the referenced fields ... correct?
For the rest, that is a text but for mqtt/agent that is a request .


Mario

[cyber]

Where is the calculation in your calculated item? All I can see is trying to add a item named "current" with exactly same key as some other item already has... Preprocessing is not a "calculated item"...
https://www.zabbix.com/documentation...pes/calculated