solution of EGS2 adding two ports in the same EPLAN is not efficient and don't protect the board failure .
for EGS4 it supports the board and port protection starting from V1R6.
The Board Protect Switch (BPS): Uses an active and a standby board. When the active board is faulty, the services are automatically switched to the standby board.
The Port Protect Switch (PPS): Uses an active and a standby board, which is similar to BPS. The difference is that only services on faulty ports are switched but services on other ports is not.