Simulation¶

Virtual process and fault-injection loop before real I/O. Simulated signals use the same project, runtime, and HMI path planned for target hardware.

Use simulation first when the next question can be answered without energizing real equipment.

Keep the simulated-to-real gap visible in the commissioning notes.

The workflow should make later hardware validation smaller, not optional.

Workflow Guide¶

This guide covers deterministic simulation runs for PLC projects without physical hardware.

1) Enable simulation mode¶

Create simulation.toml in your project folder:

[simulation]
enabled = true
seed = 42
time_scale = 8

[[couplings]]
source = "%QW0"
target = "%IX0.0"
threshold = 500.0
delay_ms = 100
on_true = "TRUE"
on_false = "FALSE"

[[disturbances]]
at_ms = 250
kind = "set"
target = "%IX0.1"
value = "TRUE"

[[disturbances]]
at_ms = 1250
kind = "fault"
message = "simulated sensor dropout"

What this does:

couplings: output-to-input wiring rules for simulation.
delay_ms: delayed effect timing.
disturbances: scripted input changes and fault injection.

2) Run with explicit simulation branding¶

trust-runtime play --project <project-folder> --simulation --time-scale 8

--simulation forces simulation mode even if simulation.toml is absent.
--time-scale accelerates simulation time (>= 1).

3) Validate behavior safely¶

Recommended checks before touching hardware:

trust-runtime build --project <project-folder>
trust-runtime validate --project <project-folder>
trust-dev test --project <project-folder> --output junit

4) Understand mode indicators¶

CLI banner shows Simulation mode and a safety warning.
TUI status panel shows mode and time scale.
Web status panel shows mode and warning.

Simulation mode is for development/test only. Do not use simulation wiring for live safety-critical outputs.