The P1 port on a digital electricity meter is typically used to read the meter and retrieve data such as electricity consumption and other related information. It is typically used by energy providers and meter reading companies to gather data and monitor energy usage in homes and businesses. The P1 port allows for the data to be read electronically, eliminating the need for a manual meter reading. However, it is not designed to allow for data to be sent back to the meter.
At the bottom of this page, I have added the “Dutch Smart Meter Requirements” (DSMR) data sheets.
Not standard (see DSMR v4.04, Chapter 4.6 “signals”)
This serial port is not standard, although it works on UART TTL level, the logical values are reversed: 1=0 and 0=1, this can be solved with software, but does not always give the desired result, the solution is to do this with hardware, example with a chip in between, often a MAX232 or 7404 is used.
According to the specification the port can handle max. 15v, so a real RS232 signal (+12v) from a “real” com port should be possible.
Plug for the P1 port.
The connector that goes into the P1 port is an RJ-11 type, 4 or 6-pin (known from the telephone lines):
Schematic representation P1 port (ESMRv5.0 P1)