Openhab 2.5 knx binding disconnecting - no reconnection

Hi there,

hope everyone is doing well in these challenging days.

I am experiencing the knx2 binding disconnecting from knxd (TUNNEL) shortly after openhab2 has started with the following error messages:

> 2020-06-08 20:05:15.564 [ERROR] [NXnet/IP Tunneling] - close connection - maximum send attempts
> maximum send attempts, no service acknowledgment received
> at ~[?:?]
> at ~[?:?]
> at ~[?:?]
> at ~[?:?]
> at ~[?:?]
> at ~[?:?]
> at ~[?:?]
> at ~[?:?]
> at ~[?:?]
> at org.openhab.binding.knx.internal.client.DeviceInfoClientImpl.lambda$0( ~[?:?]
> at org.openhab.binding.knx.internal.client.DeviceInfoClientImpl.readFromManagementClient( ~[?:?]
> at org.openhab.binding.knx.internal.client.DeviceInfoClientImpl.readDeviceDescription( ~[?:?]
> at org.openhab.binding.knx.internal.client.DeviceInspector.readDeviceDescription( ~[?:?]
> at org.openhab.binding.knx.internal.client.DeviceInspector.readDeviceInfo( ~[?:?]
> at org.openhab.binding.knx.internal.handler.AbstractKNXThingHandler.describeDevice( ~[?:?]
> at org.openhab.binding.knx.internal.handler.AbstractKNXThingHandler.lambda$0( ~[?:?]
> at java.util.concurrent.Executors$ [?:1.8.0_191]
> at [?:1.8.0_191]
> at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201( [?:1.8.0_191]
> at java.util.concurrent.ScheduledThreadPoolExecutor$ [?:1.8.0_191]
> at java.util.concurrent.ThreadPoolExecutor.runWorker( [?:1.8.0_191]
> at java.util.concurrent.ThreadPoolExecutor$ [?:1.8.0_191]
> at [?:1.8.0_191] 
> 2020-06-08 20:06:28.693 [DEBUG] [nx.internal.client.AbstractKNXClient] - Could not read value for datapoint 1/4/44: timeout waiting for group read response from 1/4/44. Going to retry.
> 2020-06-08 20:06:28.795 [DEBUG] [nx.internal.client.AbstractKNXClient] - Bridge knx:ip:tunnel is disconnecting from the KNX bus

knx thing: minimal config
Bridge knx:ip:tunnel [
] {…}

Any suggestion how to fix this?

Many thanks in advance and stay healthy


Hi, I had the same issues after upgrading to 2.5.
Did you also out commented the fetch, pingInterval and readInterval of the knx devices in your thing config? This fixed it for me.

I have an odd issue where everything works fine for a couple weeks and then knx communication stops with no errors. The bus just goes quiet until I stop/start openhab.

I might try disabling fetch/ping interval.

@Tobias, @crystollic - thanks for the hints. I changed my config accordingly, but this didn’t change too much:

2020-06-09 19:02:08.494 [DEBUG] [nx.internal.client.AbstractKNXClient] - Could not read value for datapoint 4/1/5: timeout waiting for group read response from 4/1/5. Going to retry.>
[ERROR] [NXnet/IP Tunneling] - close connection - maximum send attempts maximum send attempts, no service acknowledgment received

I have enabled logging in KARAF for KNX, but this does not reveal any hint what really went wrong. Any suggestion how to troubleshoot this issue further?



Perhaps check the number of tunnel connections? If your tunnel device supports 5 connections and both openhab and ETS are connecting that might explain why it times out after a while.

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