KNX Bridge, Things and Item channel relation

Setup, Configuration and Use Beginners
1

Hi guys,
I´ve got problems understanding this, so please make light for me here :slight_smile:

The exmples are saying this for

knx.things

Bridge knx:ip:bridge [
    type="TUNNEL",
    ipAddress="192.168.0.10",
    portNumber=3671,
    localIp="192.168.0.11",
    readingPause=50,
    responseTimeout=10,
    readRetriesLimit=3,
    autoReconnectPeriod=60,
    localSourceAddr="0.0.0"
] {
    Thing device generic [
        address="1.2.3",
        fetch=true,
        pingInterval=300,
        readInterval=3600
    ] {
        Type switch        : demoSwitch        "Light"       [ ga="3/0/4+<3/0/5" ]

and the related item

Switch        demoSwitch         "Light [%s]"               <light>          { channel="knx:device:bridge:generic:demoSwitch" }

What I dont understand is the relation from item to thing:

channel=“knx:device:bridge:generic:demoSwitch”

The Bridge in things has this uid

  • knx:ip:bridge

The thing is defined like this

  • Thing device generic

and the channel like this

  • Type switch : demoSwitch “Light” [ ga=“3/0/4+<3/0/5” ]

so I thought I´d have to define the channel like this

knx:ip:bridge:generic:demoSwitch
and not
knx:device:bridge:generic:demoSwitch

but it´s wrong unfortunately :slight_smile:

Could anyone explain me how does this work ?

Thanks!

2

You may have a look at this little post I wrote some time ago - it gives you a quick walkthrough on how things work when setting up knx things within OH.
Have fun,
Thomas

3

Hi Thomas,

cool post for real beginners, but I´m a bit farther … the question above is just something I´m curious about … my config works (with flaws :slight_smile: ) …

The only thing that I don´t understand in this context is the naming convention for the item channel

channel=“knx:device:bridge:generic:demoSwitch”

which doesn´t fit to the unid of the bridge & thing

Bridge: knx:ip:bridge Thing: generic

4

My understanding is that you access the channel on a device, thus knx:device. The gateway is then “bridge”, followed by the device “generic” itself plus the channel ID.
knx:ip would reference an IP interface. If an IP interface would have channels I’d expect it to be something like knx:ip:bridge:channelID, but this is more a theoretical idea as then you would model a device on its own reflecting it.