What the data for this category looks like
Rail transit equipment business documents mainly originate from operation and maintenance manuals, maintenance procedures, spare parts lists, operation logs, and qualification certification documents of equipment manufacturing enterprises. Data updates occur alongside new model launches, industry standard revisions, or equipment maintenance cycle adjustments, with no fixed schedule. Documents contain semi-structured chapter content, structured table content, and time-series logs. Fields and units include equipment numbers, operating parameters (rotational speed, pressure, etc.), and maintenance cycles, with corresponding units mostly being rpm, MPa, hours, or kilometers.
What constraints do these characteristics impose on the "document parsing and chunking" step
Semi-structured chapter content requires chunking to retain logical unit integrity, and prohibits splitting maintenance steps or system-divided paragraphs. Structured table content requires chunking to avoid breaking the binding relationship between fields and units, preventing the loss of associations between equipment models and quantities in spare parts lists. Time-series logs require chunking to avoid crossing time nodes, preserving the continuity of operating data. No fixed update cycle means parsing configurations must adapt to any volume of new documents without pre-adjusting rules. Individual document sizes vary widely, from a few pages of spare parts lists to hundreds of pages of operation and maintenance manuals, so chunking rules must be flexible.
How to set the configuration
Reference only; verify against the target FastGPT release and deployment documentation.
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
chunkSize | 800–1200 characters | Adapts to the average length of semi-structured chapters in rail transit equipment documents, avoiding splitting maintenance steps or parameter bindings |
chunkSplitter | By chapter title + line break | Matches the structure of equipment documents divided by system and maintenance items, retaining logical unit integrity |
customPdfParse | Enabled | Preserves table and field layout in PDFs, avoiding splitting structured data in spare parts lists |
UPLOAD_FILE_MAX_SIZE | 1000 MB | Supports upload requirements for large single operation and maintenance manuals, adapting to the single-document size of rail transit equipment documents |
PARSE_FILE_TIMEOUT_SECONDS | 600 seconds | Addresses time spent on format rendering and chunk processing during long document parsing |
chunkSettingMode | Manual configuration | Adjust chunking rules for different document types (such as spare parts lists, operation and maintenance manuals) to adapt to unique data characteristics |
Three common errors
- Symptom: After uploading a PDF operation and maintenance manual larger than 300 MB, the parsing task fails directly. Cause: The default parameters for
UPLOAD_FILE_MAX_SIZEandPARSE_FILE_TIMEOUT_SECONDSwere not adjusted, exceeding system limits. - Symptom: After configuring a custom line break as
chunkSplitter, chunking results either merge multiple independent maintenance steps or split a single equipment rotational speed parameter from its corresponding unit. Cause: Chunking rules were not adjusted based on the chapter structure of rail transit equipment documents; relying solely on line breaks cannot distinguish logical paragraphs. - Symptom: After uploading an Excel document containing an equipment spare parts list, the parsed result separates fields and units, failing to retain parameter associations. Cause: The parsing mode for structured documents was not enabled, and the default chunking rule split bound fields within tables.
How to confirm the configuration is correct
- Upload a single rail transit equipment document within the appropriate size range, and check if the parsing task completes within the preset time limit.
- Upload a spare parts list document containing structured tables, and check if the parsed chunks retain the binding relationship between equipment model, quantity, and units.
- For different document types (such as maintenance procedures, operation logs), adjust chunking rules and verify if the chunking results retain logical unit integrity.
- View the knowledge base parsing logs to confirm there are no prompts for format parsing failures or field loss.
The values provided are common starting points and should be measured against the reader's own samples.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-28.