Using Co-Processors to Activate Real Time Capabilities on Fog Nodes

Fog computing is a concept integrated in the Internet of Things (IoT) that uses advanced embedded devices, called fog nodes, in order to bring cloud services such as processing, storage and communication closer to the place where data are produced. In this paper, it is proposed an architecture for a fog node that activates the Internet of Things for the devices form industrial environment (Industrial Internet of Things - IIoT) by integrating a set of fieldbuses, such as EtherCAT, Profinet, Modbus TCP/IP, Modbus RTU, CANOpen, and Profibus. An open-source implementation of the DDS middleware protocol is used to interconnect the fog nodes. Furthermore, the fog node will meet the requirements in terms of real time, data security and integrity, latency and response time to external events. The fog node is designed and developed on an embedded device with Sitara™ AM335X processor that includes dual cores PRU-ICSS for industrial protocol. These coprocessors allow the development of application that must meet hard real time requirements.