PLC master station and ten distributed Input/Output slave station compose an annular optical fiber network, in order to make profit of the unique merits of PLCs and IPC.

• PLC主站与设置在中控室的工业PC机和各I/O子站之间采用基于Modbus_TCP/IP协议工业以太网连接，PLC主站和10个分布式I/O子站组成一个环形光纤网络，发挥了上级工业PC和下级PLC各自的优势。