PLC connectivity and tag-mapping guide

Confirm the controller interface

Record the exact controller model, firmware and enabled communication options. Check documentation for available protocols and any licensing requirements.

An interface review should be performed with the people responsible for the equipment and network. Do not assume that a read-only reporting requirement permits changes to control behavior.

Create a tag register

A tag register connects the equipment address to a meaningful application name. Document the data type, unit, scaling, timestamp policy and quality indicator.

The example below is a planning convention, not a ready-to-use WhereFy API or controller address map. Actual register addresses and permissions must be confirmed for the equipment.

Validate before expanding

Compare selected values and state transitions with the machine or meter. Verify units and scaling rather than checking only that a number appears.

Define how a bad-quality value, stale timestamp or lost connection is represented. Use explicit missing-data states instead of silently carrying an old measurement forward as current.

Illustrative tag-register fields