What the data for this category looks like
The declaration materials and file data for rail transit equipment mainly come from vehicle design drawings, type test reports, qualification approval documents, and project execution files. Data updates are triggered by new vehicle project initiation, type test milestones, or annual qualification approval volumes. Daily operations only involve minor parameter supplements. Document types include mechanical PDF drawings with layer annotations, multi-chapter structured Word declaration forms, and multi-column structured CSV test data. Fields include bogie wheelbase, traction power, test pressure, and other similar items, with corresponding units of millimeters, kilowatts, megapascals, and other similar units. Files also include structured fields such as approval nodes, submission dates, and responsible units.
What constraints these characteristics impose on the document parsing and chunking link
Mechanical PDF drawings with layer annotations cannot fully extract information using default parsing. Custom parsing is required to retain layer and annotation content. If multi-column structured CSV test data only identifies the first two columns, a large amount of key test parameters and working condition information will be lost. For long documents such as hundred-page type test reports, too short chunking will break the contextual association of the same test working condition. Too long chunking will introduce irrelevant chapter content. Chunking rules must be adjusted to match the document structure. When uploading large-volume declaration files, upload limits and parsing timeout issues are easily triggered. Targeted configuration adjustments are required.
How to set the configurations
| Configuration Item | Recommended Value Range | Rationale |
|---|---|---|
customPdfParse | Enabled | Most rail transit equipment declaration materials include PDF drawings with layer annotations. Default parsing easily loses layer and annotation information |
UPLOAD_FILE_MAX_SIZE | 500–1000 MB | Single declaration file PDFs can reach hundreds of megabytes. This range adapts to large file upload requirements |
PARSE_FILE_TIMEOUT_SECONDS | 300–600 seconds | Parsing complex test reports requires longer time. This range avoids premature termination of parsing |
chunkSize | 800–1200 characters | Adapts to contextual coherence of long paragraphs and test data tables in declaration materials |
chunkSplitter | Split by paragraph + title | Matches the chapter structure of declaration materials and retains contextual association of approval nodes |
Three common mistakes
- Symptom: File upload parsing returns a 413 error. Cause: The
UPLOAD_FILE_MAX_SIZEparameter was not adjusted, exceeding the default upload limit - Symptom: Custom parsing service calls time out. Cause: The
PARSE_FILE_TIMEOUT_SECONDSvalue was not set to a duration adapted to complex documents. The default value is too short - Symptom: Only the first two columns of CSV table data are imported. Cause: Parsing and chunking configurations were not adjusted. The default logic only identifies the first two columns of fields and does not adapt to multi-column test data
How to confirm configurations are set correctly
- Upload a single rail transit equipment declaration PDF larger than 500 MB, check that parsing completes normally without 413 errors
- Import a CSV file containing multi-column test data, confirm that all fields are correctly read without missing content
- Submit a design drawing PDF with annotations, check that the parsing result retains layer and annotation information
- Check the parsing logs in FastGPT v4.17.0, confirm that parsing duration falls within the range set by
PARSE_FILE_TIMEOUT_SECONDSwithout premature termination
The values provided here are common starting points and should be evaluated 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.