Energy meter to MQTT
Energy meters are the most common Modbus device on a site and among the fussiest to read: 32-bit values split across two registers, vendor-specific byte order, and scaling that lives in the manual rather than the device.
Typical use case
A sub-metering project with meters across several panels, feeding an energy monitoring platform. Each meter has the same register map, so one definition is reused and only the address and unit ID change.
Configuration approach
Get the register map right first
Use the Scanner against one meter to confirm what the manual says, then reuse the tag map for the rest.
Byte order
Meters differ. ABCD, BADC, CDAB and DCBA are all selectable per tag, and the Polling Tool shows the same registers reinterpreted so you can tell which is right.
Scaling
Raw counts to kW, kWh, V and A with scale and offset, so the platform receives engineering units.
Publish rate
Energy totals rarely need a one-second publish. A deadband or a periodic publish keeps the message volume sensible.
Questions engineers ask
A 32-bit value reads as nonsense. Why?
Almost always word order. A 32-bit float or integer spans two registers and vendors disagree about which holds the high word. Try CDAB against ABCD; the Polling Tool will show you both without re-reading the meter.
Build a Energy meter to MQTT gateway
Create a project, define the device and its tags in the Edge Logic Editor, and download a runtime to test at the plant.