What the data for this category looks like
Rail transit equipment declaration materials and file data originates from design output documents of equipment development units, third-party test reports, and internal approval files. Updates are completed alongside a single declaration batch, with no additional updates during the single declaration cycle. Most documents are structured PDFs and structured tables. They include fields such as project number, equipment model, key performance parameters, compliance check items, and approval circulation records. Most parameter units use common engineering units such as millimeters (mm), megapascals (MPa), and newtons (N). The length of a single document falls between 5000 and 15000 characters.
What constraints these characteristics impose on the multi-turn dialogue and prompt words workflow
The structured fields and specialized units in rail transit equipment declaration materials require consistent matching of field names in multi-turn dialogue prompt words, to avoid parameter identification errors. Single documents have substantial length, so the number of document chunks loaded per context round must be limited, to prevent exceeding the context window. Declaration batch updates have no fixed cycle, so support is required for dynamically calling documents from a specified knowledge base ID. File review requires tracing approval circulation nodes, so multi-turn dialogue must retain context of historical approval records, to avoid repeated checks of the same step.
Configuration Settings
Reference only; verify against the target FastGPT release and deployment documentation.
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
| Maximum context length | 8000–12000 characters | Matches the average length of a single declaration document, to avoid truncating critical parameters |
| Number of documents recalled per single request | Top 6 | Adapts to the field density of rail transit equipment declaration materials, to avoid interference from redundant information |
chatId binding rule | Associate with the current declaration batch ID | Ensures multi-turn dialogue context only links to materials from the current declaration, without loading historical documents |
messages context limit | Retain the most recent 15 dialogue turns | Controls the context window size, to avoid exceeding system limits |
variables storage method | Global persistent | Adapts to fixed parameters such as project number and equipment model that must be retained during the declaration process |
| Prompt word preset | Include a compliance field check list | Reduces repeated input, and improves review efficiency |
Three Common Misconfigurations
- Phenomenon: Historical declaration files are automatically loaded during multi-turn dialogue. Cause:
chatIdis not bound to the current declaration batch, so the system defaults to associating with global context. - Phenomenon: An error occurs when setting a knowledge base ID variable. Cause:
variablesis not configured for global persistence, or the variable format does not meet system requirements. - Phenomenon: Some dialogues do not retrieve the declaration material knowledge base, and return generic responses. Cause: The prompt words do not explicitly require calling the knowledge base, or the context window overflows, causing knowledge base recall to fail.
How to Verify Correct Configuration
- Upload a single rail transit equipment declaration document, initiate the first dialogue, and confirm that returned results only link to the currently uploaded document.
- Initiate a multi-turn dialogue, enter a question containing specialized parameters, and confirm that the system correctly identifies fields corresponding to units such as millimeters (mm) and megapascals (MPa).
- Attempt to update a global variable, initiate a new dialogue, and confirm that the variable value is retained without being reset.
- Initiate a review request that relies on the knowledge base, and confirm that the system always calls the declaration material knowledge base, without returning generic responses.
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.