@chrisdutz and me will join forces in coming week (4-5 May 2019) to hack around few things which are necessary in order to get plc4x running in openHAB runtime. Once this will be completed we will have a good base to move forward and implement binding.
For everyone who is interested in topic, there is public event we will be part off co-organized by European Comission and Apache Software Foundation.
Participation is open and if you live around Brusels or will to travel then come by! There is lots to be covered - ie. Beckhoff ADS and many more which could be interesting for industrial applications.