Yes, the ethernet port on F1616 provides up to 6 server connection and 1 client connection. This means that while you are doing online monitoring, you can simultaneously use Excellink to log data, use a SCADA or Touch panel to connect to the PLC via Modbus/TCP and still have some spare connection.
The PLC can also open a client connection to another MODBUS TCP server and then use READMODBUS and WRITEMODBUS function via virtual port COMM4 to talk to the external TCP/Server. This can be done while the server connections mentioned above are still in active connection.
What we mentioned above are just the Ethernet connection only. The F1616 PLC still has 1 RS232 port and 2 R485 serial ports, all 3 support MODBUS ASCII and RTU and these can also be used in master or slave mode while the Ethernet communication is happening.