DSMR P1 Port Standard: How Dutch Smart Meters Share Data With Your Home

The Netherlands has one of the most consumer-friendly smart meter ecosystems in the world, largely thanks to the DSMR P1 port — a standardised data output on every Dutch smart meter that lets any device read live energy and gas data. Here is everything you need to know.

What is DSMR?

DSMR (Dutch Smart Meter Requirements) is the technical standard published by Netbeheer Nederland (the Dutch DSO association) that defines all requirements for smart meters deployed in the Netherlands. It covers:

Metrological requirements (accuracy, measurement)
Communication to the utility (P2 port — DLMS/COSEM over GPRS/4G)
Local customer interface (P1 port — open data port)
Gas meter communication (M-Bus wired connection from gas meter to electricity meter)

The current version is DSMR P1 Companion Standard v5.0.2, applicable to all meters deployed since 2016.

The P1 Port: Technical Specification

The P1 port is a physical RJ11 (telephone) connector on the front of every Dutch smart meter. It outputs a data stream using a modified version of the IEC 62056-21 Mode D protocol.

Physical Interface

Connector: RJ11 6P6C (6-pin)
Pin 1: +5V power (max 250 mA — enough to power a microcontroller)
Pin 2: Request line (pull low to enable telegram output)
Pin 3: Data ground
Pin 5: Data (inverted serial, 115200 baud, 8N1, in DSMR v5)
Pin 6: Power ground

Data Format: The P1 Telegram

The P1 telegram is a text-based format (based on IEC 62056-21 mode D) that is human-readable. A telegram is sent every second in DSMR v5. Example (abbreviated):

/FLU5\253769484_A

0-0:1.0.0(240614213045W)        ! Timestamp
1-0:1.8.1(000123.456*kWh)       ! Active energy import T1
1-0:1.8.2(000089.123*kWh)       ! Active energy import T2
1-0:2.8.1(000000.000*kWh)       ! Active energy export T1
1-0:2.8.2(000000.000*kWh)       ! Active energy export T2
0-1:24.2.3(240614213045W)(00456.789*m3)  ! Gas meter reading

!CRC16

The data uses OBIS codes (same as DLMS) — making it easy to integrate with any system that understands DLMS object addressing.

DSMR v5 vs v4: Key Differences

Feature	DSMR v4	DSMR v5
Baud rate	115200	115200
Telegram interval	10 seconds	1 second
Instantaneous power	No	Yes (per-phase W)
Instantaneous current/voltage	No	Yes (per phase)
CRC	CRC16	CRC16
Power supply on P1	5V (limited)	5V (250 mA)

What Data is Available on P1?

OBIS Code	Description
`1-0:1.8.1`	Active energy import, tariff 1 (off-peak), kWh
`1-0:1.8.2`	Active energy import, tariff 2 (peak), kWh
`1-0:2.8.1`	Active energy export, tariff 1, kWh
`1-0:2.8.2`	Active energy export, tariff 2, kWh
`1-0:1.7.0`	Current active power import, kW
`1-0:2.7.0`	Current active power export, kW
`1-0:32.7.0`	Instantaneous voltage L1, V
`1-0:52.7.0`	Instantaneous voltage L2, V
`1-0:72.7.0`	Instantaneous voltage L3, V
`1-0:31.7.0`	Instantaneous current L1, A
`0-1:24.2.3`	Gas meter reading (via M-Bus), m³

The P1 Ecosystem

The open P1 port has created a thriving ecosystem of consumer devices and home automation integrations:

SLIMMEMETER.COM P1 Dongle: WiFi-connected P1 reader, widely used
Home Assistant P1 integration: native support via the DSMR component
DSMR-logger project: open-source Raspberry Pi P1 reader
Energy monitors: brands like Homewizard, Iungo, Plugwise all use P1
Solar inverter integration: P1 data used to optimise PV self-consumption

Why Other Countries Should Copy This

The P1 port is arguably the single best policy decision in smart metering globally. It:

Gives consumers real-time visibility of their energy use with no utility involvement
Enables a competitive home energy management market
Does not compromise the metrological integrity of the meter (P1 is read-only)
Costs virtually nothing — an RJ11 connector and a UART output

Contrast with the UK SMETS2 approach, which requires the DCC intermediary for any consumer data access — adding latency, cost, and complexity. The Dutch P1 approach proves that open consumer ports and accurate metering are completely compatible.