MQTT Item receives NULL only

Hi Community,

I have a strange issue with an MQTT Item which only receives Null.

Item:

Number MCU2_SYS_Runtime_db “MCU2 SYS Runtime [%f.0 ms]” (per) {mqtt="<[MQTT:MCU2/SYS/Runtime:state:default]"}

Errormessage

2017-08-13 14:19:12.563 [WARN ] [.c.i.events.EventPublisherImpl] - given new state is NULL, couldn’t post update for ‘MCU2_SYS_Runtime_db’

MQTT

~ $ mosquitto_sub -h openhab -v -t "MCU2/SYS/Runtime"
MCU2/SYS/Runtime 6586

Does anybody know what is wrong here and how to fix it?

Thanks
Manuel

Topic seems OK.
Is your broker really “MQTT” ? Not mosquitto or mqtt ? Check your mqtt.cfg
Group is (per), OK
You are Formatierung with ‘f’ floating point The result is formatted as a decimal number, but the input seems to be INT(decimal) not Float “6686” maybe this is the problem.

I thought mqtt is mosquitto. And my broker name is MQTT.
In fact it is only this item / topic which is not working and same warning in the openhab.log.
Also tried it with “%d” as integer without success.

Number MCU2_SYS_VOLT_db “MCU2 SYS Volt [%d mV]” (per) {mqtt="<[MQTT:MCU2/SYS/Volt:state:default]"}
Number MCU2_SYS_Runtime_db “MCU2 SYS Runtime [%d ms]” (per) {mqtt="<[MQTT:MCU2/SYS/Runtime:state:default]"}

Event.log:

grep VOLT /var/log/openhab/events.log
2017-08-14 09:03:19 - MCU2_SYS_VOLT_db state updated to 2790.0000
2017-08-14 09:08:48 - MCU2_SYS_VOLT_db state updated to 2788.0000

openhab.cfg

mqtt:MQTT.url=tcp://openhab.fritz.box:1883
mqtt:MQTT.clientId=OpenHabLive
mqtt:MQTT.qos=1
mqtt:MQTT.retain=true
mqtt:MQTT.async=true

Mosquitto
An Open Source MQTT v3.1/v3.1.1 Broker

MQTT is messaging protocol for use on top of the TCP/IP protocol.
A MQTT Broker is like a Server that manages in- and outgoing messages.

This does still not solve you problem… I know that…

Whait a sek…

Are you using openHAB 1.X ?

Thanks for explaning, i was just confused.

Yes I am still on 1.x and even not the lastest. Migration to 2.x is already on my agenda.
Does this change something?