Tags, decoding, import & alarms
Turn registers into trustworthy values, reusable definitions, and runtime alarm rules.
Tags, decoding, import & alarms
Views answer “what should Busloom read?” Tags answer “what does the data mean?” A tag begins at one PDU address and may consume one bit, one word, or several consecutive words depending on its codec.
Tag anatomy
- Identity
- Name, address space, starting PDU address, group, and manual order.
- Codec
- Boolean, signed/unsigned integer, float, ASCII, hexadecimal, or binary plus required register count.
- Layout
- Byte and word order for multi-register values.
- Engineering semantics
- Scale, offset, precision, unit, limits, and value labels.
A safe decoding workflow
Name the raw location
Create the tag with the correct address space and PDU address. Do not compensate for addressing mistakes with a scale or word swap.
Choose the codec
Match the vendor's width and signedness. Ensure the source view includes every consumed word.
Prove layout
Use hexadecimal raw words and a known device value to establish byte/word order.
Apply scale and offset
Only after the raw numeric value is correct, add the documented engineering conversion.
Add presentation
Set unit, precision, value labels, and limits. These should communicate meaning, not hide uncertainty.
Test boundary values
Verify zero, negative values, high range, or enumerated states where possible.
Import a vendor register map
Busloom imports CSV, TSV, and XLSX through a preview rather than guessing column meaning. Choose whether source addresses are PDU offsets or documentation addresses, map columns to Busloom fields, review validation errors, then decide whether conflicts add only or update existing tags.
| Mechanism | What it reuses | Important behavior |
|---|---|---|
| Import preset | Column mapping and address interpretation for another file with the same shape | Import/export/delete one preset at a time |
| Public device definition | Reviewed views, tags and metadata from the busloom-devices catalogue | Preview before import; applying copies ordinary data and the project stays self-contained |
| Tag export | A portable review or spreadsheet round-trip of project tags | Use when exchanging a register map without a complete project |
The public catalogue is data-only. A definition cannot provide endpoints, credentials, certificate material, automation, or executable code. Refreshing the catalogue never mutates an existing project; import is always an explicit, reviewable edit.
Runtime tag alarms
A numeric tag can define high or low rules with clearing hysteresis. Boolean and enumerated state rules compare against an exact decoded value. Every rule may require the condition to remain true for an activation delay before it becomes active.
| State | Meaning | What happens next |
|---|---|---|
| Pending | Condition is true but its activation delay has not elapsed | Returns to normal without creating an active event if the condition clears |
| Active | The rule has triggered | Remains a live condition until the decoded value crosses the configured clearing boundary |
| Acknowledged | An operator has seen an active alarm | Does not clear or disable the rule; the active row keeps its alarm state |
| Cleared | The decoded value returned to normal | The current state normalizes while the bounded session transition remains available |
Tag alarms are evaluated from native acquisition events. Definitions live in the project; pending/active state, acknowledgement and transition history are session-only. Export current state and history as CSV, TSV, XLSX, JSON or JSON Lines when the evidence must leave the session.