Connections
On this page
The Connections page is where you define every data source the application communicates with. A connection is a protocol adapter — it handles the communication between the application and a PLC, database, cloud service, or memory store. Every tag must belong to a connection, so configuring connections is the first step in any project.
The Connections page
The page opens as a tile view. Each configured connection appears as a card showing the connection name, protocol type, and a coloured status bar indicating live communication health. A green status bar means the connection is active and polling data successfully. A red or amber bar indicates a communication fault.
A built-in Global Memory connection is always present in every project. It appears with a green Persistence label and requires no configuration. Global Memory is a simulated in-memory store whose values survive application restarts — useful for intermediate calculations, counters, and demo projects that do not require physical hardware.
Adding a connection
Click the + Add Connection tile on the Connections page. The connection creation dialog opens.
Type a descriptive name in the Name field. Choose a name that identifies the device and its role — for example Compressor_PLC, Line3_Energy_Meter, or SCADA_OPC. The name appears on the tile and in the Tag Database.
Click Set to commit the name. The connection configuration form opens.
Choose the protocol from the Type dropdown. The form updates to show the parameters relevant to that protocol.
Enter the required parameters for the chosen protocol. For EtherNet/IP this is the PLC’s IP Address, Slot number, and Refresh rate. For MQTT this is the broker address and topic. Refer to the field descriptions next to each input.
Click Next to proceed to Step 2, where you can browse the device’s data points and map them as tags in the Tag Database.
Save the connection. Return to the Connections page and confirm that the connection tile’s status bar turns green, indicating successful communication.
All tags that belong to a deleted connection are permanently removed from the Tag Database. Any components bound to those tags will lose their data source. Export or document your tag list before deleting a connection that has tags mapped to it.
Database
The SQL database driver reads values from relational databases by running user-defined SQL queries whose results map to tag values. Supported engines: MySQL, PostgreSQL, Microsoft SQL Server, and SQLite. Useful for pulling reference data, setpoints, or production records from an existing enterprise database.
EtherNet/IP
Ethernet/IP is a widely used communication protocol for industrial automation, enabling real-time data exchange between PLCs and SCADA systems using CIP (Common Industrial Protocol) over standard Ethernet. The native driver communicates directly with Allen-Bradley and Rockwell Automation PLCs — ControlLogix, CompactLogix, and MicroLogix families — without requiring an OPC server. Supports online tag import from the PLC’s tag database.
Learn more about EtherNet/IP →
EtherNet/IP (Micro800)
A variant of the EtherNet/IP driver optimised for the Micro800 family of Allen-Bradley controllers (Micro820, Micro830, Micro850, Micro870). Use this type instead of the standard EtherNet/IP adapter when connecting to these controllers.
Learn more about EtherNet/IP →
Global / Local Memory
Global and Local Memory provide virtual registers stored entirely within the application’s own memory — no physical PLC hardware required. Global Memory values persist between application restarts; Local Memory values reset on restart. Use cases include auxiliary calculation variables, running totals that reset each shift, cross-tag communication, and demo or test projects without physical hardware.
Learn more about Global / Local Memory →
Loxone
Connects to a Loxone building automation Miniserver. Exposes the Miniserver’s virtual inputs and outputs as tags for display and monitoring.
MQTT
MQTT (Message Queuing Telemetry Transport) is a lightweight protocol for IoT and machine-to-machine communication. The driver acts as an MQTT client, subscribing to topics from an external broker. Two models are supported: publish/subscribe (topic-based), where devices publish to a topic and others subscribe; and device-to-device, where messages are exchanged between individually identified devices. This is the inbound MQTT connection for receiving data — distinct from any outbound MQTT broker publishing.
Modbus TCP / UDP
Modbus TCP and Modbus UDP are Ethernet-based variants of the Modbus protocol. Modbus TCP communicates over TCP/IP with reliable connection-oriented messaging; Modbus UDP is faster and suits time-critical or simple read-only applications. Connects to PLCs, energy meters, variable-speed drives, and sensors. Both variants use the standard Modbus addressing model — holding registers, input registers, coils, and discrete inputs — identified by function code and register number.
OPC UA
OPC UA (Unified Architecture) is a communication standard developed by the OPC Foundation. It provides a browseable address space, allowing data point discovery without knowing addresses in advance. The OPC server acts as an intermediary — all communication is mediated by the OPC server’s configuration rather than direct PLC access. Key advantages: Security — modern cryptography with TLS encryption and certificate-based authentication; Scalability — interoperability across different vendors and systems.
REST API
Polls HTTP/REST endpoints on a configurable interval using standard HTTP GET requests. Use it for web services, cloud APIs, or any device that exposes data over HTTP. Supports custom headers and authentication tokens.