Sampling and Scaling

The Sampling and Scaling section controls when data is read or written and how raw values are converted to meaningful engineering units. These settings shape the cadence and fidelity of your collected measurements and, for write-enabled tags, how frequently outbound measurements are sent.

Read Sampling Interval

The read sampling interval applies to Read tags, and defines how the Data Connection is queried or subscribed to for new measurements.

On Change

Use On Change to receive updates as soon as the source changes. This is event-driven and ideal for low latency. However, if data changes at a high rate at the data source, it can potentially generate large amounts of data. Availability: only connectors that support push/subscription semantics has this option (e.g., MQTT, OPC UA).

Periodic

Use Periodic to poll the source at a fixed interval (e.g., every 1000 ms). This is useful when the source does not push updates or when you want a fixed data resolution. Keep intervals realistic for device and network capacity; extremely short intervals may overload field devices or networks. Note: not all connectors support polling.

Scaling Factor

The scaling factor is a multiplier applied to raw values to convert them into different engineering units:

scaled_value = raw_value × scaling_factor

Examples:

• Converting t (tonnes) → kg: scaling factor = 1000

• Converting kg → t (tonnes): scaling factor = 0.001

A scaling factor of 1 disables scaling.

Tips

• Ensure the factor matches the units produced by the source so downstream consumers see consistent units.

• Apply the factor once at collection to avoid double-scaling later in processing.

Example Tag configuration for a Read Tag that polls data every 10 seconds and does not scale the values.

Write Interval (only for Write tags)

For Write tags, the write interval determines when new data points are sent to the destination Data Connection.

On Change

On Change writes immediately when the source tag provides a new measurement. Use this for near-real-time command/setpoint propagation.

Periodic

Periodic writes the latest available measurement at the chosen interval, even if it hasn’t changed. Use this when receivers expect a heartbeat or regular refresh.

Example Tag configuration for a Write Tag that writes measurements directly to the output on every change.