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Daisy Chain Redundancy Switching

Our frequency converters utilize the patented “Daisy Chain” integrated switching technology. The Daisy Chain design removes the relays associated with a centralized protection switch tray and distributes them across the individual converters. We were awarded patent 5,666,646 on this distributed protection switch topology.

The Daisy Chain configuration is designed to chain the IF input and RF output of up to 12 online converters together through Transmit Switch Modules (TSMs) terminating in a backup converter. When a fault occurs in an online converter, the TSM in the converter with the fault is commanded to switch to the backup converter. The backup converter performs the fault detection, self reconfiguration and the logical switching functions. If the backup converter has a fault, it will not attempt to perform the protection switching task. If the backup converter does not have a fault, it will assume the frequency and attenuation of the faulted on-line converter, and compensate for the chain losses.

The backup converter in the Daisy Chain communicates with the online converters through a High-Speed (data interface) Bus (HSB). When faults are detected the backup converter re-configures itself to replace the on-line converter with the fault. The backup converter also uses the HSB to monitor configuration changes made to the on-line converters by either remote control or front panel command inputs. Changes in frequency, attenuation or polarity are entered into the backup table as they are made, as well as information from new on-line units. The HSB does not interfere with the remote control communications link for access to any of the converters in the Daisy Chain.

Daisy Chain Redundancy Switching Example