Shelly Pro 3EM (three-phase)

Status: Unverified · Register points: 30 · Transports: Modbus TCP

A curated ModDef profile for the Shelly Pro 3EM (three-phase). Import it as shelly.pro-3em or load the .moddef.yaml directly.

Connect to one over Modbus TCP and watch its values live in the device dashboard.

Usage

Load the profile, bind a transport, and read a point by name. The runtime applies the offset, scaling, byte order, and sentinels from the definition.

Go

doc, _ := moddef.Load("shelly-pro-3em.moddef.yaml")
dev, _ := client.New(doc, "shelly-pro-3em", transport) // your modbus.Transport
v, _ := dev.ReadPoint(ctx, "neutral_current")
fmt.Println(v)

TypeScript

import {Device} from '@moddef/core';
import {loadDocument} from '@moddef/core/node';

const doc = await loadDocument('shelly-pro-3em.moddef.yaml');
const dev = Device.create(doc, 'shelly-pro-3em', transport);
console.log(await dev.readPoint('neutral_current'));

Rust

let doc = moddef_core::load("shelly-pro-3em.moddef.yaml")?;
let mut dev = Device::new(&doc, Some("shelly-pro-3em"), transport)?;
let v = dev.read_point("neutral_current").await?;

Python

from moddef import Device, load
from moddef.pymodbus import Options, PymodbusTransport

doc = load("shelly-pro-3em.moddef.yaml")
transport = await PymodbusTransport.tcp("192.168.1.50", options=Options())
dev = Device.create(doc, "shelly-pro-3em", transport)
print(await dev.read_point("neutral_current"))

C

md_doc_t doc;
md_doc_init(&doc, flash_ptr, flash_len);        /* zero-copy view */

md_dev_t dev;
md_dev_init(&dev, &doc, MD_STR("shelly-pro-3em"), &transport);

md_value_t v;
md_dev_read(&dev, MD_STR("neutral_current"), &v);

C++

auto doc = moddef::Document::view(flash_bytes).value();   // zero-copy over flash
auto dev = moddef::Device::open(doc, "shelly-pro-3em", transport).value();

if (auto v = dev->read("neutral_current"); v)
    std::cout << v->to_string() << '\n';

Measurands

The 7 semantic quantities this device reports, each linked to the measurand catalog. Query a device by measurand instead of a raw point when you want portable code.

Base quantity	Name	Unit	Description
voltage	Voltage	V	RMS voltage; qualify with phase_ref (L1_N, L1_L2, ...)
current	Current	A	RMS current; qualify with phase_ref / direction
active_power	Active Power	W	Instantaneous real power
apparent_power	Apparent Power	VA	Instantaneous apparent power
power_factor	Power Factor	1 (ratio)	Ratio of real to apparent power (dimensionless)
frequency	Frequency	Hz	Grid frequency
energy_active	Active Energy	Wh	Cumulative active energy register

Source

• Profile: energy-meter/shelly-pro-3em/shelly-pro-3em.moddef.yaml
• Register map: vendor documentation