PLC AC500 V3 MODBUS TCP

Dear Expert,

We want to configure AC500 V3 PM5650 as Redundant controller, we have some doubt :

1. Can We use CI522 for redundant IO to PM5650 redundant controller instead using CS31?
2. Do we need added license for Modbus TCP Server/Client program "PS5601-HA-MTCP"?
3. For PM5650 with 2 ethernet Port, do we need to add communication card CM597 for modbus TCP or we can use onboard ethernet port on controller for Modbus TCP Server/Client?
4. Can we configure both Modbus TCP Client and Server on same port ?

Thanks,

DZ