How to delay thing activation after bridge activation

I created a Xbee binding using Digi devices.
I would need to set a delay between the Bridge activation and the Thing activation to avoid the following error message :

2017-02-17 10:32:42.215 [DEBUG] [s.core.common.SafeMethodCaller:199 ] - Timeout of 5000ms exceeded, thread safeCall-1 (76) in state TIMED_WAITING is at java.lang.Thread.sleep(

Any idea ?