This paper designs and implements an IIoT (Industrial Internet of Things) platform based on MMS (Manufacturing Message Specification) with enhanced security through unidirectional data transmission. Unidirectional gateways that are used to overcome transferring between separated industrial networks based on UDP (User Datagram Protocol), are capable of transferring information between networks. However additional gateways are required for network connectivity. The proposed platform supports unidirectional communication between networks using MQTT (Message Queue Telemetry Transport) broker, which acts as a gateway used in unidirectional communication. In addition, MoM protocol (MMS over MQTT) is designed using publishing and subscription functions of MQTT. In order to evaluate the performance of the proposed platform, performance of UDP that used in the existing unidirectional gateway, is compared. Simulation results show that the proposed platform has a slower transmission time then UDP, but the reliability of data transmission is higher when a large number of packets are transmitted to the one port.
Keywords: Industrial networks, MMS, Real-time, IoT