Which protocol is most commonly associated with facilitating communication between different devices in an OT network?

Modbus is the most commonly associated protocol for facilitating communication between different devices in an Operational Technology (OT) network. It is a widely adopted communication protocol that is specifically designed for industrial applications, allowing for data exchange between devices like PLCs (Programmable Logic Controllers), sensors, and other automation equipment.

The simplicity and effectiveness of Modbus make it a popular choice in various industries, including manufacturing and energy, where devices from multiple vendors need to communicate seamlessly. Modbus can operate over different mediums, including serial lines and TCP/IP networks, making it versatile for different implementations.

In contrast, while the other protocols listed have their own unique applications, they are not as broadly used for general communication in OT networks. DDS, for example, is geared more towards real-time data exchange in distributed systems, rather than the straightforward device communication that Modbus excels at. CAN is primarily used in automotive applications and embedded systems, focusing on vehicle communication rather than the broader industrial context. SIS refers to a safety system used for risk reduction in hazardous processes, and does not serve the primary communication role that Modbus fulfills in an OT environment.