Introduction

The DataTalk OT/IT Gateway solves a fundamental problem in industrial environments: OT devices each speak a different protocol, but IT systems expect a unified data stream. The gateway sits between these two worlds — it reads from any device in its native language, and delivers the data onwards in whatever format the destination requires.

The core idea

The gateway works in three stages:

1 — Read from OT devices using native industrial protocols. No driver installation, no middleware, no adapters. Define a Connection and the gateway starts polling immediately. Supported protocols include Modbus TCP/UDP, EtherNet/IP (Allen-Bradley), OPC UA, Siemens OPC UA, MQTT Client, REST API, SQL databases, and local memory registers — all handled in a single project.

2 — Normalize into a unified Tag Database. Every value from every device, regardless of protocol, becomes a named Tag. An EtherNet/IP register from a Rockwell PLC and a Modbus register from an energy meter sit side by side in the same database, scaled to engineering units, with alarm limits and logging configuration applied uniformly.

3 — Forward to IT systems in one or more directions simultaneously:

• MQTT Broker — the gateway becomes its own MQTT broker; external clients connect and subscribe to live tag values
• OPC UA Server — exposes the full Tag Database as a browseable OPC UA address space; SCADA systems and historians connect and read or subscribe as standard OPC UA clients
• Gateway — the gateway actively pushes data outward to: Azure IoT Hub, Amazon AWS IoT Core, SQL databases, REST API endpoints, or any external MQTT broker — on a timer or event trigger, with no external system needing to initiate the connection

Quick start

The fastest way to see the gateway in action: connect a Modbus TCP device, map a few register addresses to named tags, and immediately read those same values from any OPC UA client — without any middleware or custom code.

See the step-by-step guide: Modbus to OPC UA.

Application layout

The UI is divided into a left navigation panel and a right content area that supports multiple simultaneously open pages as tabs.

The left panel has three tabs: Project (the main configuration tree), TagDB (the equation editor and linked external tables), and Assets (the reusable HMI component library).

The Project tree is organized in three sections:

Data Interface — everything that brings data in and sends it out:

• Connections — inbound protocol connections to OT devices
• Tags — the unified data model (Tag Database, Ranges, UDT, Categories)
• Gateway — outbound active data forwarding to cloud and IT systems

Accesses — who and what can reach the gateway:

• User — operator and engineer accounts with role-based permissions
• API Tokens — machine-to-machine access for automated integrations

Settings — system-wide configuration:

• General — languages, audit logging, security policy
• Data Servers — the passive outbound servers (MQTT Broker, OPC UA Server)
• Storage — disk usage, historical datalog retention
• Backup — project snapshots and restore

Key capabilities

Multi-protocol inbound — Modbus, EtherNet/IP, OPC UA, Siemens, MQTT, REST, SQL, and local memory in one project. No per-protocol middleware.

Unified tag model — all device data normalized to named tags with engineering units, scale factors, alarm limits, categories, and logging groups — regardless of source protocol.

Passive outbound servers — built-in MQTT Broker and OPC UA Server let any compatible client connect and read live data without any configuration on the client side.

Active outbound Gateway — push data to Azure IoT Hub, AWS IoT Core, SQL databases, REST APIs, and external MQTT brokers on a schedule or event trigger — no client needs to initiate the connection.

Historical logging — configurable datalog groups (fast / default / slow) store tag history from 100 ms to 15 min intervals with configurable retention periods.

Role-based access control — per-user groups, 2FA, API tokens, and operator startup screens for secure, tailored workflows.

Reusable configuration — User-Defined Types (UDT) for equipment templates, shared Ranges for alarm thresholds, Categories for large-scale tag organization.