I have 2 Redundant Servers connected to 2 Redundant PLC's through 2 ethernet switches.

Server-1 Port-1 connected and Server-2 port-1 to Switch-1. PLC-A is connected to switch-1.
Server-1 Port-2 connected and Server-2 port-2 to Switch-2. PLC-B is connected to switch-2.

My selection in Redundancy Setting is Software Redundancy. Redundancy mode is Non-Dominant.

If Primary server is shutdown/ Runtime closed then standby server is changing over to Primary and status updating in SCADA and in both the servers it is showing the same information.
But when any Ethernet cable is failed/ removed from server/ ethernet switch failed then
the status in SERVER-1 showing as Server-1 primary server, standby server OFF
and status in SERVER-2 showing as Server-2 primary server, standby server OFF even when both servers are ON and Runtime is ON.

Can any one help me out from this.

I'm Reading the Status of Servers for System driver variable i.e., [Network] Standalone/Primary Server/Standby Server/Client.