A link in Protolinker defines the connection between two tags.

While tags represent individual pieces of data, a link specifies how that data flows from one protocol to another.

In other words, links are the “wires” inside Protolinker that move values between different systems.

Why Links Are Important #

Links make it possible to translate and route information across protocols. Without links, tags would remain isolated to their original source.

With links, you can:

• Connect legacy devices to modern platforms (e.g., Modbus → MQTT).
• Synchronize values between two different systems.
• Control data flow with transformations or conditions applied during linking.

How Links Work in Protolinker #

1. Source Tag
   • A link starts with a source tag, which represents the original data point (e.g., temperature from a Modbus register).
2. Destination Tag
   • The link then points to a destination tag, where the data will be delivered (e.g., sensor/temperature on MQTT).
3. Data Flow
   • Once the link is active, every update on the source tag is automatically reflected in the destination tag.
4. Optional Transformation
   • Links can include scaling, unit conversion, filtering, or scripts to adjust values before delivery.

Example #

• Source Tag: temperature (from Modbus, value = 25.3 °C).
• Link: Connects temperature → sensor/temperature.
• Destination Tag: Published over MQTT as sensor/temperature = 25.3.

This way, links ensure that different protocols can share the same information seamlessly, without manual handling or duplication.