Feldbusgeschwindigkeiten

Feldbusgeschwindigkeit, or fieldbus data rate, refers to the maximum rate at which a fieldbus network can transfer useful data between automation devices such as sensors, actuators, and controllers. This data rate, together with network topology and protocol features, directly affects control loop cycle times, diagnostics, and overall system responsiveness. Fieldbus speeds vary widely across standards, ranging from tens of kilobits per second in some process-oriented networks to hundreds of megabits per second in Ethernet-based implementations.

Different fieldbus families define their own speed regimes. Classic digital fieldbuses include Profibus and Foundation Fieldbus, which offer a mix of slower, highly robust modes and higher-speed options for real-time communication. For example, some Profibus variants reach up to 12 Mbps, while Foundation Fieldbus provides slower H1 links for sensor/actuator networks and faster HSE links for backbone connectivity. CAN-based fieldbuses (such as CANopen) typically operate up to 1 Mbps, balancing speed with noise immunity and long cable runs. Ethernet-based fieldbuses and real-time Ethernet protocols (such as Profinet, EtherCAT, and EtherNet/IP) leverage standard Ethernet speeds—10/100 Mbps, 1 Gbps, and higher—with real-time extensions to deliver deterministic communication.

When selecting a fieldbus and its speed, engineers weigh requirements such as deterministic timing, distance, channel count, diagnostics, and environmental conditions. Higher data rates can reduce cycle times and enable richer data exchange but may demand more complex hardware and stricter EMI protection. Conversely, lower speeds can enhance robustness and simplicity at the cost of bandwidth and responsiveness.