Cut-Through Switching with DCS and FCS Error Path Detection
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Solution Overview
Problem
In industrial network systems, existing technologies cannot identify the transmission path where errors occur, especially when using the cut-through switching method, leading to continuous forwarding of error frames and inability to distinguish between errors caused by the transmission path or receiving devices.
Innovation Solution
A communication apparatus that calculates and compares DCS and FCS codes within the frame to determine errors, allowing for error detection and path identification without circulating faulty frames, even in cut-through switching scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the cut-through switching method is used to reduce forwarding delay time, then real-time processing performance is improved, but the ability to identify transmission path errors is lost
Solution Approach 1:
The patent segments the error detection process into two distinct parts: DCS (Data Check Sequence) for detecting errors in data fields and FCS (Frame Check Sequence) for detecting errors in the entire frame including transmission path errors. This segmentation allows the system to maintain cut-through switching performance while enabling precise error identification by comparing results from both check sequences.
Solution Approach 2:
The patent introduces an intermediary error detection mechanism that operates during cut-through switching by calculating and comparing DCS and FCS codes. This intermediary process enables error identification without requiring complete frame reception, thus maintaining the speed benefits of cut-through switching while restoring error detection capability.
2Measurement precision
If error frames are continuously forwarded to ensure error detection, then error identification capability is improved, but network efficiency deteriorates
Solution Approach 1:
The patent performs preliminary error detection by calculating the DCS code during the forwarding process in cut-through switching. By comparing the calculated DCS with the received DCS before complete frame transmission, the system can identify errors early and prevent unnecessary continuous forwarding of error frames, thus maintaining network efficiency while improving error identification capability.
Solution Approach 2:
The patent implements a feedback mechanism where the results of DCS and FCS comparisons are used to determine whether to continue forwarding frames. This feedback allows the system to stop forwarding error frames promptly, preventing network congestion and maintaining high productivity while ensuring accurate error identification.
Data Source
AI summary
A CRC calculating unit calculates a DCS code for a DA field to a DATA field and an FCS code for the DA field to a DCS field. A DCS checking unit outputs a DCS check result with a calculated DCS code and a DCS code in the DCS field to a terminal operating unit. An FCS checking unit outputs an FCS check result with a calculated FCS code and an FCS code in the FCS field to an FCS converting unit. The FCS checking unit determines whether to forward through the frame or to forward the frame by storing the calculated FCS code in the FCS field based on the FCS check result. The terminal operating unit determines a processing mode based on the DCS check result.