# Goal State — Layered Architecture

LAYER 1 — EQUIPMENT

PLCs, CNCs, OPC UA-native devices

One OPC UA session per device; OtOpcUa holds it.

LAYER 2 — OtOpcUa

Equipment namespace + System Platform namespace (absorbs LmxOpcUa)

Clustered, site-local. Single sanctioned OPC UA access point per site.

LAYER 3 — SCADA

Aveva System Platform (validated) · Ignition (KPI)

Derives canonical machine state from raw signals.

LAYER 4 — ScadaBridge

IT/OT bridge — central integration layer

Deadband, store-and-forward, producer to Redpanda.

ScadaBridge central is the sole IT↔OT crossing point.