Kempton Retrofit HMI

Retrofit run control

Gateway polls PLC/RTU tags, evaluates detectors locally, records to NowRetro

Record ticks to NowRetro

Idle. Each step advances the plant 10 simulated minutes; detections, incidents and actions are written back to NowRetro (the phone owner may be asked to confirm each write).

Select an asset from the Estate view.

SERVICENOWOT Service Management · instance thameswater.service-now.com (simulated) · integration user svc.coconut.edge

Incidents

cmdb_ci = OT asset

Select an incident.

MCP calls to NowRetro

every read and write this page makes

timetoolstatementresultms

Cypher console

read-only recommended

How the retrofit is wired

L1 · PLC-5/40, RTUsModbus TCP · DNP3 · EtherNet/IP

L2 · Legacy HMIIntellution FIX 6.15 / RSView32 / ClearSCADA — untouched

L3.5 · NowRetro gatewayreads tags read-only, runs detectors, writes graph memory

Edge SLMexplains detections using recalled incidents; never in the control loop

ServiceNowEvent → Incident on cmdb_ci; Flow approval → allow-listed action back to gateway

PLC interlocksfinal authority: gateway only sets request bits inside PLC-enforced bands

Action tiers: T0 record T1 auto + notify T2 approval in ServiceNow T3 advisory only. Comms faults are routed to Telemetry, never to maintenance.

Memory search

fulltext over SLM notes