Real-time communication in factories manages the data exchange between control units such as programmable logic controllers (PLC) and field devices including motor drives, sensors, and actuators. Depending on the manufacturing requirements, this data communication can occur within seconds to microseconds

In slower processes like those in the gas and oil industries, where temperature and pressure changes are gradual, communication occurs in the range of tens to hundreds of milliseconds. For factory automation with conveyor belts and automated machinery, data communication can occur in the range of hundreds of microseconds to tens of milliseconds.

In robotics and motor drive applications, data exchange must occur faster due to the need for rapid updates to motor controllers and position data, ranging from 31.25 microseconds (corresponding to a 32kHz control loop) to a few hundred microseconds.

PLCs report status and diagnostic information to upper layers, providing information to the plant control and operator. Industrial networks can also communicate with the cloud, enabling operators to monitor and control the plant from remote locations.

To achieve periodic data exchange, components have to meet requirements for different OSI model layers. For instance, the physical (PHY) layer and media access control (MAC) layer must fulfill specific real-time data communication requirements. Standard Ethernet MACs may introduce jitter and delay or may not support on-the-fly data processing required by specific industrial protocols.

Furthermore, the system's exposure to the internet necessitates security features to protect data communication. The European Cyber Resilience Act, for example, adds such requirements for plant manufacturers.