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.