KNX energy metering: a starting checklist

Metering joins KNX through three common paths. Pulse counters consume the dry-contact output on legacy meters and convert it to a KNX counter group address. S0 interfaces follow the same idea but use the standard S0 protocol. M-Bus meter gateways translate full meter telegrams (active power, energy, voltage, current, power factor) into a rich set of KNX data points.

The richer your data, the more useful your dashboards. A pulse counter alone gives you cumulative energy, useful for billing but not for diagnostics. An M-Bus gateway exposes instantaneous active power per phase, which lets you see in real time whether a tenant is overloading a circuit, whether the air conditioner is running outside scheduled hours, and where standby loads are creeping in.

A good starter list of group addresses per metered circuit: instantaneous active power (DPT 14.056), cumulative active energy (DPT 13.010), tariff index, status (online or offline), and a billing-period reset trigger. Send each to a visualization server that handles aggregation and charting. Avoid storing high-frequency historical data on the bus itself; the bus is for control, not analytics.

Document the meter inventory carefully. The handover pack should include meter manufacturer, model, serial, channel mapping to KNX group addresses, and the location of each meter in the cabinet. Without this information, a future fault becomes a treasure hunt.

Finally, plan tariff support up front if the customer is on a time-of-use rate. Add a tariff group address that switches between peak, standard, and off-peak so consumption can be reported in those buckets at the visualization layer.