CI840 CPU spare parts ▏ABB module ▏Robot system

Title: Configuring Redundant Optical Rings in Fieldbus Networks

Introduction: Ensuring the seamless functioning of a segmented field bus network is critical for optimal performance. This article explores the steps and conditions required to establish a redundant optical ring configuration, enhancing network reliability.

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1. • Segmentation is automatically lifted when both modules confirm the correct functioning of the segmented field bus network, facilitated by test frames.
   • The network then self-organizes into a ring structure.
2. Conditions for Network Configuration:
   • Fulfilling specific conditions is crucial for the successful operation of the network.
   • Conditions include settings for the operating mode (“Redundant optical ring”) on both optical ports of optical link modules (Hirschmann).
3. Ring Formation Guidelines:
   • All modules within a ring must be interconnected via fiber lines, with no inclusion of an RS485 bus line.
   • In case of redundancy events, such as a line break, a brief switching time occurs, impacting data transmission.
   • To ensure a smooth transition, setting the frame repeat (Retry) on the PROFIBUS master to at least 3 is recommended.
4. Post-Error Handling:
   • After correcting an error, no frames should be present in the network during the transformation of the optical line back into an optical ring.
   • This precaution prevents potential disruptions that may arise when a master attempts to address a non-existent device.
5. Configuration Requirements for Redundant Optical Ring:
   • The parameter HSA (Highest Station Address) must be set to a value at least one greater than the highest address of a subscriber in the bus segment.
   • The slot time should be adjusted to approximately twice the value required in a non-redundant network.
6. Avoiding Configuration Failures:
   • Failure to meet the above requirements can lead to the optical line not closing into a redundant optical ring after segmentation.

CI840 CPU spare parts ▏ABB module ▏Robot system

Conclusion: Configuring redundant optical rings in fieldbus networks requires careful consideration of settings and conditions. Adhering to these guidelines ensures a robust network that can seamlessly recover from errors and interruptions, providing enhanced reliability and performance.