The updated NET Concentrator System (NCS) provides users with increased options for communications. With the addition of the EMM Interface Module, the process control and distributed I/O network comes standard with an Ethernet (Modbus/TCP) port and dual, independent Modbus RTU (RS-485) ports. One or both of the Modbus RTU ports can be configured as Modbus master ports, allowing the system to poll other Modbus RTU slaves with the network polling functions of a typical Modbus master. The system can be used as either a single or dual Modbus master, allowing it to provide simultaneous Ethernet and dual Modbus RTU master/slave communications.