Onkyo binding floods log with "no route to host"

My receiver and some other devices are disconnected from power to save the 30W standby consumption. I can turn on power via the Homematic binding. Unfortunately when power is off, the Onkyo binding floods the openhab log with the following entries:

2017-01-28 18:21:04.538 [ERROR] [b.binding.onkyo.internal.eiscp.Eiscp] - Can't connect: No route to host
2017-01-28 18:21:04.541 [ERROR] [b.binding.onkyo.internal.eiscp.Eiscp] - Error occurred during message waiting
java.io.IOException: Not Connected to Receiver
        at org.openhab.binding.onkyo.internal.eiscp.Eiscp.waitStateMessages(Eiscp.java:477)[212:org.openhab.binding.onkyo:2.0.0]
        at org.openhab.binding.onkyo.internal.eiscp.Eiscp.access$1(Eiscp.java:338)[212:org.openhab.binding.onkyo:2.0.0]
        at org.openhab.binding.onkyo.internal.eiscp.Eiscp$DataListener.run(Eiscp.java:503)[212:org.openhab.binding.onkyo:2.0.0]

I think the the error log level should be changed to DEBUG so that it does not appear in the log anymore.

[vbier]

I would log a warning on first connection problem and set thing status to OFFLINE with correct error message. Any further connection problems as long as thing status is OFFLINE can then be ignored as they are expected in OFFLINE state. That way you still get something in the log with default logging setup and do not flood the log anymore. If you want, you can additionally log something with INFO level when connection has been (re)established so you can keep track of when the receiver had been connected.

[kaikreuzer]

But reason for communication error can’t be see from the status.

That’s not correct. You can (and should!) set the reason as a third parameter when setting the status. This is logged as an event and it is also shown to the user in the Paper UI.

Could you describe what is the purpose of the different logging levels?

Done here now: http://docs.openhab.org/developers/development/guidelines.html#e-logging