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SCADA & MQTT Integration with SMX-RNS20

The SMX-RNS20 can act as an IoT gateway, polling data from connected PLCs and HMIs via its Remote IO drivers (Siemens S7, Modbus TCP, OPC UA) and forwarding that data to an external MQTT broker or cloud SCADA platform.

This enables real-time dashboards and alerts without requiring SCADA software to have a direct VPN connection to the machine network.

  1. First, configure Remote IO data points (see the relevant Remote IO guides). You need at least one active data source before configuring MQTT.
  2. Log in to the SMX-RNS20 web interface → Cloud → MQTT.
  3. Click Add Publisher. Enter your broker’s address (hostname or IP), port (default 1883 for plain, 8883 for TLS), and credentials if required.
  4. Set the topic prefix (e.g., factory/line1/smx-001/).
  5. Map each Remote IO data point to an MQTT topic. The SMX publishes the value, timestamp, and quality as a JSON payload.
  6. Set the publish interval (cyclic) or configure on-change publishing.
  7. Save. The device will start publishing immediately — check your broker’s topic tree to verify.

Most modern SCADA systems support MQTT subscriptions. Common integrations:

SystemIntegration
Ignition (Inductive Automation)MQTT Engine module — subscribe to the SMX topic prefix directly
AVEVA (Wonderware)System Platform MQTT client or InTouch Access Anywhere
GrafanaUse the MQTT data source plugin (e.g., via InfluxDB → Telegraf MQTT consumer)
Node-REDMQTT In node → any downstream processing or dashboard node

Architecture diagram: SMX-RNS02 → AWS IoT Core → Kepware → WinCC SCADA Architecture — data flow from SMX-RNS20 via AWS IoT Core MQTT to Kepware and WinCC SCADA

AWS IoT Core — Manage → Things → Create single thing AWS IoT Core — Manage → Things: click Create single thing

AWS IoT Core — certificate addition during thing creation AWS IoT Core — certificate creation step

AWS IoT Core — download certificate, private key, and Root CA Download all certificate files: device certificate, private key, Amazon Root CA 1

AWS IoT Core — Test page, Subscribe to topic AWS IoT Core Test — subscribe to your topic to verify incoming MQTT data

SMX-RNS20 — Settings → Cloud Connector Settings → Cloud Connector: configure Host, Client ID, Region, certificate files

SMX-RNS20 — Modules → Cloud Topic Modules → Cloud Topic: select which data to publish

SMX-RNS20 — Status → Cloud showing connected Status → Cloud: confirm MQTT connection is active

Kepware installation wizard Kepware KEPServerEX — start installation

Kepware — Custom installation type Select Custom installation to choose MQTT Client component

Kepware — MQTT Client component selection Select the MQTT Client component during installation

Kepware — system tray icon Settings menu Kepware system tray: open Settings → Certificate Store

Kepware — Certificate Store: import AWS certificates Certificate Store → MQTT Client: import the AWS certificates downloaded earlier

Kepware Configuration — new channel creation Kepware Configuration: create a new channel

Kepware — channel naming Name the MQTT channel

Kepware — channel MQTT settings Channel settings: AWS IoT endpoint, port, client ID

Kepware — add tags using TOPIC_NAME+VAR_NAME format Add tags under the channel — use TOPIC_NAME+VAR_NAME format

Kepware OPC Quick Client — verifying live tag values OPC Quick Client — confirm Kepware is reading MQTT values successfully

WinCC — create new project WinCC: create new project

WinCC Tag Manager — Add new driver → OPC Tag Manager: Add new driver → OPC

WinCC — OPC server selection (Kepware) Select the Kepware OPC server from the computer list

WinCC — browse and add Kepware tags Browse Kepware tags and add them to the WinCC project

WinCC Graphic Designer — tags added to page Graphic Designer: add displays bound to the MQTT-sourced tags

WinCC Graphic Designer — SCADA page layout SCADA page layout in Graphic Designer

WinCC — running project displaying live MQTT values Running project — live values from the field device via SMX-RNS20 → AWS IoT Core → Kepware → WinCC