Hello
Welcome to the forum.
It possible but pricey.
You need Red Lion CSMSTRV2/CSMSTRLE .
Connect one RS232 port to one PLC the other port to other PLC.
The software is free and the comunication cable is USB.
Chose the tags you want and its work.
I just conected AB SLC500 to S7-200.And Omron to Koyo by TCP/IP.
You can get good support here since Dan from Red Lion is memeber here.
All the best