This paper proposes a robust Openflow controller to be applied in software-defined real-time Ethernet (RTE) at industrial Ethernet network applications. The proposed scheme enhances the controller by introducing a novel delay module, based on the real-time requirements. The delay module works to guarantee zero packet losses with lower delays during traffic flow transmission. Performance evaluation was conducted to analyze the delay module performance, and the results ensure zero packet losses. Development of the robust controller helps to mature the Openflow itself, to be more reliable and powerful for real-time environment in the future.