Hi Maciej,
I tried out your solution, but the Howdy Process never received the signal event from the Data Drive Process. Just to double-check, are you using jbpm 5.3.0 and then executing the process within the jbpm-console? I can successfully get the solution to work from a unit test that extends JbpmJUnitTestCase, but from the jbpm-console, I never see the signal received.
Thanks,
- Darin