  The Industrial Internet of Things (IIoT) has already become a part of our
everyday life be it water supply, smart grid, or production, IIoT is
everywhere. For example, factory operators want to know the current state of
the production line. These new demands for data acquisition in modern plants
require industrial components to be able to communicate. Nowadays, network
communication in Industrial Control Systems (ICSs) is often implemented via an
IP-based protocol. This intercommunication also brings a larger attack surface
for hackers. If an IIoT device is influenced by attackers, the physical process
could be affected. For example, a high network load could cause a high Central
Processing Unit (CPU) load and influence the reaction time on the physical
control side. In this paper, we introduce a dual Microcontroller Unit (MCU)
setup to ensure a resilient controlling for IIoT devices like Programmable
Logic Controllers (PLCs). We introduce a possible solution for the demand of
secure architectures in the IIoT. Moreover, we provide a Proof of Concept (PoC)
implementation with a benchmark and a comparison with a standard PLC.
