If both Masters are configured to accept all messages they will both receiver the same message from the slaves. Note however that the installation feature in RC1180-MBUS2 to bind slaves to a master. If you do this you can change the Master mode to only accept installed slaves. This is described in details in the MBUS User Manual.
Last Update: January 18, 2018
January 18, 2018 4459 Wireless M-Bus Q&A