The SMI Simulation

The SMI Simulation is a family of simulated measuring instruments with realistic physics, built for training and rehearsal: the complete certification workflow runs against it with no hardware involved. Each instrument in the family is a Simulated SMART Measuring Instrument Twin (SST), and an SST serves the same governed twin interface that a physical SMART instrument serves, so software, and people, cannot tell the difference from the served side.

Meet the simulated instruments →

Like the twin it rehearses, the SMI Simulation belongs to the SMART+ tier; the split below says plainly what runs today (the whole demo rehearses on it) and what is roadmap.

What you can do today

• Run the whole certification workflow against a simulated instrument. The live demo certifies the simulated Steelyard LC-500 load cell against the modelled R 60, application to decision; sign-in runs through the identity service, with the demonstration cast assumed as personas.
• Watch a simulated quarter’s surveillance. The demo’s twin console monitors the served feed: drift flags the certificate, an outage degrades verdicts to indeterminate, a served fault opens a service case (sign in as Admin, then provision the demo twin).
• Meet the four instruments. A strain-gauge load cell (OIML R 60; creep and thermal hysteresis), a continuous gas monitor (OIML R 144; drift classes and cross-sensitivity), a Doppler speed meter (OIML R 91; cosine error and rain fade, which lose readings rather than inventing them), and an optical conveyor dimensioner (OIML R 129; sampling, reflectance, ambient-light noise), on the SMI Simulation site.
• Drive the world channel. An operator places loads, sweeps the environmental conditions, injects faults, and advances the virtual clock; the bench renders the physical scene beside an analogue dial, the ground truth a human reads with their eyes.
• Inspect the machinery. Primmel SST, the framework (primmel/sst: the kind-agnostic runtime, the shell, the bench, the specifications), and OIML SST, the instrument library (oimlsmart/sst: the kinds, the instances, the composites), are public repositories.

How it works

Each SST presents two channels. The /twin channel is the governed projection, and its schema is generated from the manufacturer’s product reference package; a startup conformance check stops the instrument if the served interface drifts from the package. The /world channel is the physical world: the operator’s loads, faults, and clock. An epistemic wall separates the two: certification logic reads only the served channel, and the world channel answers to the operator. That wall is how the classroom teaches the lying-twin lesson: the API reports what it reports, and the needle shows what is true.

The SMI Simulation is driven from the platform, not beside it: the platform’s gateway consumes the /twin channel through its standard connector registry, and the interaction contract is two endpoints and four verbs. Because the served schema is generated from the same product reference packages the platform reads, an SST proves the supply chain it simulates: a package edit that changes the served interface fails the instrument’s own startup check. Primmel SST is part of the open Primmel work the program adopts (the Primmel language site carries the ownership story); OIML SST is the OIML SMART program’s content on top of it.

Today (SMART) and the vision (SMART+)

Why it exists

Certification skills are learned on instruments that are expensive, scarce, and slow to fail in instructive ways. Platform changes need a rehearsal space where a verdict chain can be exercised end to end before it touches a real evaluation. And a certification system that is never shown a failing instrument cannot demonstrate what failure looks like. The SMI Simulation supplies instruments that behave honestly, fail on purpose, and reset in seconds.

Who may use it, and who may run it

The hosted SMI Simulation is part of the program’s member surfaces, and the self-host determination is under programme review; the cells marked “proposed” below are the programme’s proposal, not yet confirmed policy. Quoted from the program’s single entitlement source:

The honest questions

Does a simulation prove anything about real instruments? It proves the workflow and the supply chain, not the physics of a specific device: the served schema is generated from the same product reference packages the platform reads, so an edit that changes the interface fails the instrument’s own startup check. What the SMI Simulation certifies is the certification machinery itself.

Can a simulated instrument lie? Yes, and that is the point. The bench shows the physical scene beside the served values; the classroom’s central lesson is reading the dial against the API. The twin-certification program’s probe channel exists because served values alone are never the whole truth.

Why not rehearse on production instruments? Because production instruments are busy being evidence. The rehearsal space must be free to fail: drift on purpose, outage on schedule, fault injection on demand, reset in seconds.

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