Product:
Interface module, ComPacT NSX, Modbus SL HUB LV434224
Resolution:
Terminal VW3A8306RC, you can insert it to any port of the three ports on the final Modbus SL hub. If all ports are occupied, You can use the terminal block VW3A8306DRC connector to add the termination as shown in the second picture below.
The terminal VW3A8306DRC, you need to connect it only to the final Modbus SL hub.