ENM-223-R1 3-Phase Power Quality & Energy Metering Module

Firmware Version: 2025-09 snapshot

ENM-223-R1 — 3-Phase Power Metering & I/O Module

HOMEMASTER – Modular control. Custom logic.

Module Description

The ENM-223-R1 is a configurable smart I/O module designed for 3-phase power quality and energy metering.
It includes 3 voltage inputs, 3 current channels, 2 relays, and optional 4 buttons / 4 LEDs, with configuration via WebConfig using USB-C (Web Serial).
It connects over RS-485 (Modbus RTU) to a MicroPLC/MiniPLC, enabling use in energy monitoring, automation, and smart building applications.

Table of Contents

• 1. Introduction
• 2. Use Cases
• 3. Safety Information
• 4. Installation & Quick Start
• 5. MODULE-CODE — Technical Specification
• 6. Modbus RTU Communication
• 7. ESPHome Integration Guide (if applicable)
• 8. Programming & Customization
• 9. Maintenance & Troubleshooting
• 10. Open Source & Licensing
• 11. Downloads
• 12. Support

1. Introduction

1.1 Overview of the ENM‑223‑R1 Module ⚡

The ENM‑223‑R1 is a modular 3‑phase energy metering + I/O device for power monitoring, automation, and local control. It features 3 voltage channels (L1/L2/L3‑N), 3 current channels (external CTs), 2 SPDT relays, 4 user LEDs, and 4 buttons—all driven by an RP2350 MCU with QSPI flash and a dedicated ATM90E32AS metering IC.

It integrates with MiniPLC/MicroPLC controllers or any Modbus RTU master over RS‑485, and it’s configured in‑browser via USB‑C Web Serial (no drivers). Typical uses include energy dashboards, demand response, alarm‑driven relay control, and building automation. Defaults ship as Modbus address 3 @ 19200 8N1 (changeable in WebConfig).

Quick device flow:
Wire Lx/N/PE + CTs → set address/baud in WebConfig → calibrate gains/offsets → define alarms per L1/L2/L3/Totals → map relays/LEDs/buttons → connect RS‑485 A/B (and GND if separate PSUs) → poll via Modbus.

1.2 Features & Architecture

Core Capabilities

1.3 System Role & Communication 🍰

The ENM‑223‑R1 is a smart Modbus RTU slave. It executes local alarm logic (thresholds & acks) and mirrors states/values to a PLC or SCADA via registers/coils. Configuration (meter options, calibration, relay/LED logic, button actions, Modbus address/baud) is done via USB‑C WebConfig, stored to non‑volatile memory.

Note: The UI exposes per‑channel Alarm / Warning / Event with min/max thresholds and Ack required option; relays can follow selected alarm kinds or be Modbus‑controlled. Buttons can toggle/override relays; LEDs reflect overrides or alarm states.

2. Use Cases

This section outlines practical application examples for the ENM‑223‑R1 module. Each use case includes a functional goal and a clear configuration procedure using the WebConfig tool and/or Modbus RTU integration.

These templates are applicable in energy management, automation, industrial control, and building infrastructure deployments.

2.1 Overcurrent Alarm with Manual Reset

Purpose: Activate Relay 1 when current exceeds a configured threshold and hold it until manually acknowledged.

Configuration:

• Alarms → Channel: Totals
  • Enable Alarm
  • Metric: Current (Irms)
  • Max threshold: e.g. > 5000 (for 5 A)
  • Enable Ack required
• Relays → Relay 1
  • Mode: Alarm Controlled
  • Channel: Totals, Kinds: Alarm
• LEDs → LED 1
  • Source: Alarm Totals, Mode: Steady
• Acknowledge: via Web UI, Modbus coils 610–613, or front panel button (if assigned)

2.2 Manual Override for Load Control

Purpose: Allow field operators to override Relay 2 using a button, regardless of Modbus or automation control.

Configuration:

• Relays → Relay 2
  • Mode: Modbus Controlled
  • Enabled at power-on
• Buttons → Button 2
  • Action: Override Relay 2 (hold 3s)
• LEDs → LED 2
  • Source: Override R2, Mode: Blink or Steady

Holding the button for 3 seconds enters override mode. A short press toggles the relay. Holding again exits override mode.

2.3 Environmental Voltage/Frequency Alarm with Auto-Clear

Purpose: Detect power quality faults (sag/swell or freq drift), activate Relay 1 as an output, and auto-reset when back in range.

Configuration:

• Alarms → Channel: L1
  • Enable Alarm
  • Metric: Voltage (Urms)
  • Min: 21000 (210 V), Max: 25000 (250 V)
  • Leave Ack required unchecked
• Relays → Relay 1
  • Mode: Alarm Controlled, Channel: L1, Kinds: Alarm
• LEDs → LED 1
  • Source: Alarm L1

2.4 Staged Load Shedding via Modbus Scenes

Purpose: Use a controller to shed non-critical loads as power consumption increases.

Configuration:

• Relays → Relay 1 and Relay 2
  • Mode: Modbus Controlled
• In PLC logic:
  • Monitor Totals S (VA) via Input Register
  • If S > 8000, write coil 600 = OFF (Relay 1)
  • If S > 10000, write coil 601 = OFF (Relay 2)
  • Restore relays when values drop below defined hysteresis limits

Ideal for HVAC or lighting where priority-based power shedding is needed.

Summary Table

🛠 All parameters are configurable via USB‑C WebConfig. Modbus control assumes master-side logic (PLC, SCADA, or MicroPLC/MiniPLC).

3. Safety Information

These safety guidelines apply to the ENM‑223‑R1 3‑phase metering and I/O module. Ignoring them may result in equipment damage, system failure, or personal injury.

⚠️ Mixed Voltage Domains — This device contains both SELV (e.g., 24 V DC, RS‑485, USB) and non-SELV mains inputs (85–265 V AC). Proper isolation, wiring, and grounding are required. Never connect SELV and mains GND together.

3.1 General Requirements

3.2 Installation Practices

3.3 I/O & Interface Warnings

⚡ Power

🧲 Inputs & Relays

🖧 Communication & USB

🎛 Front Panel

🛡 Shielding & EMC

✅ Pre‑Power Checklist

• All wiring is torqued, labeled, and strain-relieved
• No bridge between logic GND and GND_ISO
• PE and N are wired to terminals
• RS‑485 A/B polarity and 120 Ω termination confirmed
• Relay loads do not exceed 5 A or contact voltage rating
• CTs installed with correct polarity and securely landed
• Voltage inputs fused, protected, and within spec (85–265 V AC)

🧷 Tip: In single-phase installations, energize L1 and tie L2/L3 → N to prevent phantom voltages.

4. Installation & Quick Start

The ENM‑223‑R1 connects to your system over RS‑485 (Modbus RTU) and supports configuration via USB‑C WebConfig. Setup involves:
1) Physical wiring, 2) Digital setup (WebConfig → Modbus or PLC/ESPHome control).

4.1 What You Need

Quick Path
① Mount → ② wire 24 VDC + RS‑485 (A/B/COM) → ③ connect USB‑C → ④ launch WebConfig →
Set Address/Baud → assign Inputs/Relays/LEDs → confirm data → ⑤ disconnect USB → hand control to Modbus master.

4.2 Power

The ENM‑223‑R1 uses 24 V DC input for its interface domain and internally isolates metering circuits.

• Power Terminals: Top left: V+ and 0V
• Voltage Range: 22–28 V DC (nominal 24 V)
• Typical Current: 50–150 mA (relays off/on)
• Protection: Internally fused, reverse-polarity protected
• Logic domain: Powers MCU, RS‑485, LEDs, buttons, relays

4.2.1 Sensor Isolation

• Metering IC (ATM90E32AS) is powered from an isolated 5 V rail
• Analog domain uses GND_ISO, fully isolated from GND
• Do not connect GND_ISO ↔ GND; isolation via B0505S + ISO7761

Only voltage inputs (Lx-N) and CTs connect to the isolated domain.

4.2.2 Power Tips

• Do not power relays or outputs from metering-side inputs
• Use separate fusing on L1–L3
• Tie L2, L3 → N if using single-phase only (prevents phantom voltage)
• Confirm PE is wired — improves stability & safety

4.3 Networking & Communication

4.3.1 RS‑485 (Modbus RTU)

Physical

Cable & Topology

• Twisted pair (with or without shield)
• Terminate with 120 Ω at each bus end (not inside module)
• Biasing resistors (pull-up/down) should be on the master

Defaults

🧷 Reversed A/B will cause CRC errors — check if no response.

4.3.2 USB‑C (WebConfig)

Purpose: Web-based configuration tool over native USB Serial. Supports:

• Live readings
• Address/baudrate config
• Phase mapping
• Relay/button/LED logic
• Alarm setup
• Calibration (gains/offsets)

Steps

1. Connect USB‑C to PC (Chrome/Edge)
2. Open tools/ConfigToolPage.html
3. Click Connect, select ENM serial port
4. Configure settings: address, relays, LEDs, alarms, calibration
5. Click Save & Disconnect when finished

⚠️ If Connect is greyed out: check browser support, OS permissions, and close any other apps using the port.

4.4 Installation & Wiring

Use diagrams and explain:

• Inputs
• Relays
• Sensor rails (12/5V)
• RS-485 terminals
• USB port

4.5 Software & UI Configuration

The ENM‑223‑R1 is configured using the browser‑based WebConfig Tool
(tools/ConfigToolPage.html) over USB‑C.
No drivers or software installation is required — configuration happens directly via Web Serial API (Chrome/Edge).

• WebConfig refreshes live data every 1 s.
• Click into a field to pause refresh for that field.
• Press Enter to apply a change.
• All settings are stored in non‑volatile flash.

1) Modbus Setup (Address & Baud)

• Click Connect and select the USB serial port.
• The Active Modbus Configuration bar shows the current Address and Baud Rate.
• You can configure:
  • Modbus Address: 1–255 (default = 3)
  • Baud Rate: 9600 / 19200 / 38400 / 57600 / 115200 (default = 19200)
• Changes are live and applied on selection.
• If you change baud or address, remember to reconnect the controller with updated settings.

2) Meter Options & Calibration

Meter Options

• Line Frequency: 50 / 60 Hz (affects metering IC behavior)
• Sum Mode:
  • 0 = algorithmic (P = P1 + P2 + P3)
  • 1 = absolute (P = |P1| + |P2| + |P3|)
• Ucal (gain): global voltage scaling multiplier
• Sample Interval (ms): rate at which readings update (10–5000 ms)

Calibration (per phase A/B/C)

• Ugain / Igain: scaling gains (16-bit, 0–65535)
• Uoffset / Ioffset: calibration offsets (signed)
• Press Enter after editing to write the value to the module.

3) Alarms / Inputs (Per‑Channel Rules)

The ENM has 4 measurement channels: L1, L2, L3, and Totals.

Each channel supports:

• 3 rule slots: Alarm, Warning, Event
• Metric types:
  • Voltage (Urms)
  • Current (Irms)
  • Active Power P
  • Reactive Power Q
  • Apparent Power S
  • Frequency

You can configure:

• Enable toggle
• Metric, Min, and Max thresholds
• Ack required — latches the Alarm state until acknowledged

Acknowledgment:

• Press Ack L1–L3 / Totals in UI
• Or write to Modbus coil (610–613)

💡 ENM has no digital inputs (DIs). These rules are “virtual inputs” based on real-time metering data.

4) Relay Logic Modes

Each of the two onboard SPDT relays can be configured independently.

Options:

In Alarm Controlled mode, direct Modbus writes may be blocked when an alarm is active.

5) Button & LED Mapping

Buttons (1–4)

Each button can be mapped to:

• None
• Toggle Relay 1/2
• Toggle LED 1–4
• Override Relay 1/2 (hold 3s)
  • Hold 3 s to enter override
  • Short press toggles the relay
  • Hold again to exit override

User LEDs (1–4)

Each LED has:

• Mode: Steady (when active) or Blink (when active)
• Source:
  • Override R1/R2
  • Alarm, Warning, Event — for any channel
  • Any (A|W|E) — a combined indicator per channel

💡 Use Override R1 as LED 1 source to give a clear local override status.

6) Live Meter & Energies

Live Meter View:

• U (V), I (A), P (W), Q (var), S (VA)
• PF, angle, frequency, temperature
• Totals and per-channel tiles
• Phase validation and wiring checks

Energies:

• Per phase + totals:
  • Active (+ / –) in kWh
  • Reactive (+ / –) in kvarh
  • Apparent in kVAh

Use this screen to verify CT orientation, load phase mapping, and live alarm behavior during commissioning.

4.6 Getting Started (3 Phases)

Phase 1 — Wire

• 24 V DC to V+ / GND (top left terminals)
• Voltage inputs: PE / N / L1 / L2 / L3
  • For single-phase: energize L1 only, tie L2/L3 → N
• CTs to CT1/CT2/CT3 with correct ± polarity (1 V or 333 mV RMS)
  • Arrow → load; shielded pairs preferred
• RS‑485 A/B/COM
  • Use shielded twisted pair; terminate bus ends with 120 Ω
• (Optional) Relay outputs: COM/NO/NC
  • Add snubber on inductive loads (RC/TVS)
• Ground panel PE and avoid bridging GND ↔ GND_ISO

👉 See: Installation & Quick Start

Phase 2 — Configure (WebConfig)

• Open tools/ConfigToolPage.html in Chrome/Edge
• Connect via USB‑C → Select port → Connect
• Set:
  • Modbus Address / Baud
  • Line Frequency, Sample Interval
  • Alarm thresholds per L1/L2/L3/Totals
  • Relay modes: Alarm or Modbus Controlled
  • Map Buttons & LEDs (override, Ack, follow alarms)
  • (Optional) Adjust U/I gains, save calibration

👉 See: WebConfig UI

Phase 3 — Integrate (Controller)

• Connect controller via RS‑485
• Match Modbus address / baud
• Poll:
  • Input registers: meter values (U, I, P, Q, S, PF, angle, kWh, etc.)
  • Coils: relays (600/601), Ack (610–613), button state
• Send:
  • Coil writes: toggle relays, acknowledge alarms
• Use with:
  • HomeMaster MicroPLC / MiniPLC
  • SCADA / ESPHome

👉 See: Modbus RTU Communication & Integration Guide

✅ Verify

5. ENM-223-R1 — Technical Specification

5.1 Diagrams & Pinouts

System Diagram	MCU Pinout
Field Board Terminal Map	MCU Board Layout

💡 Note: Pinouts correspond to hardware revision R1. Terminals are pluggable 5.08 mm pitch (26–12 AWG, torque 0.5–0.6 Nm).

5.2 I/O Summary

5.3 Absolute Electrical Specifications

🧩 Values validated from schematics and manufacturer datasheets for ATM90E32AS, ISO7761, B0505S-1WR3, HF115F, AP64501.

5.4 Connector / Terminal Map (Field Side)

5.5 Reliability & Protection Specifics

• Primary Protection: Reverse-path diode + MOSFET high-side switch; distributed inline fuses
• Isolated rails: Independent +12 V / +5 V DC with LC filters; isolated returns (GND_ISO)
• Inputs: Per-channel TVS and RC filtering; debounced in firmware
• Relays: Coil driven via SFH6156 optocoupler → S8050 transistor → HF115F SPDT; RC/TVS suppression recommended for inductive loads
• RS-485: TVS (SMAJ6.8CA) + PTC; failsafe bias on idle; TX/RX LED feedback
• USB: PRTR5V0U2X ESD array on D+/D–; CC pull-downs per USB-C spec
• Memory Retention: FM24CL16B FRAM for energy counters (>10¹⁴ writes); W25Q32JV QSPI flash for firmware/config

5.6 Firmware / Functional Overview

• Alarm Engine: Four channels (L1–L3 + Totals); each has Alarm/Warning/Event rules
  • Modes: Active-while / Latched-until-ack
  • Metrics: Urms, Irms, P, Q, S, Frequency
• Relay Control: Per relay Enable / Invert / Group mode; Manual override (hold 3 s) via buttons
• LED Feedback: User-assignable LEDs for Alarms / Overrides / Events (Steady or Blink)
• Setup & Telemetry: WebConfig over USB-C; configure Modbus addr/baud, relay groups, thresholds, and live readings
• Data Retention: Energy and configuration stored in FRAM (non-volatile, instant writes)

5.7 Mechanical Details

ENM-223-R1 Physical Dimensions (DIN-rail enclosure)

5.8 Standards & Compliance

6. Modbus RTU Communication

The ENM‑223‑R1 communicates over RS‑485 (Modbus RTU) and supports:

• Real-time metering via Input Registers
• Configuration via Holding Registers
• Control and acknowledgment via Coils
• Status monitoring via Discrete Inputs

The device acts as a Modbus Slave and can be polled by a PLC, SCADA, ESPHome, or Home Assistant system.

6.1 Addressing & Protocol Settings

📌 Use the WebConfig tool over USB‑C to set Modbus address and baud rate.

6.2 Input Registers — Real-Time Telemetry (FC04)

6.3 Energy Registers (Wh/varh/VAh, FC04)

Energy values are 32-bit unsigned integers (Hi/Lo word pairs).

6.4 Holding Registers — Configuration (FC03/06/16)

6.5 Coils — Output Control (FC01/05/15)

6.6 Discrete Inputs — Read-only Status (FC02)

6.7 Scaling Summary

6.8 Polling Best Practices

• Typical polling rate: 1 s for live data (powers, voltages, current)
• Energy: poll less often (e.g. every 5–10 s)
• Batch reads: Use FC04 and FC03 with multi-register reads for speed
• Avoid writing frequently to EEPROM-backed registers (e.g., Ucal or gains)
• Coils: Fast updates (e.g. overrides) okay; no debounce needed

🛠 To reduce bus collisions, stagger multiple ENMs on a shared RS‑485 bus using different poll intervals and address spacing.

6.9 Modbus Integration Example (MiniPLC)

modbus_controller:
  - id: enm223
    address: 3
    modbus_id: rtu_bus
    update_interval: 1s

sensor:
  - platform: modbus_controller
    modbus_controller_id: enm223
    name: "Urms L1"
    register_type: read
    address: 100
    value_type: U_WORD
    unit_of_measurement: "V"
    accuracy_decimals: 2
    filters:
      - multiply: 0.01

switch:
  - platform: modbus_controller
    modbus_controller_id: enm223
    name: "Relay 1"
    register_type: coil
    address: 600

7. ESPHome Integration Guide (MicroPLC/MiniPLC + ENM‑223‑R1)

The HomeMaster controller (MiniPLC or MicroPLC) running ESPHome acts as the Modbus RTU master over RS‑485. It polls one or more ENM‑223‑R1 modules and publishes all sensors, relays, LEDs, and alarms into Home Assistant.

No Home Assistant add-ons are required — all logic runs on the ESPHome controller.

7.1 Architecture & Data Flow

• Topology: Home Assistant → ESPHome (MicroPLC) → RS‑485 → ENM‑223‑R1
• Roles:
  • ENM: metering, alarm rules, relays, LEDs, buttons
  • ESPHome: Modbus polling, sensor/relay control, entity publishing
  • HA: dashboards, energy view, automations

LED mappings, alarm logic, and override behavior are configured on the ENM module (via WebConfig). Home Assistant only reacts to exposed states.

7.2 Prerequisites (Power, Bus, I/O)

1. Power

• ENM: 24 V DC → V+ / 0V
• Controller: per spec
• If separate PSUs: share COM/GND between controller and ENM

2. RS‑485 Bus

• A—A, B—B (twisted pair), COM shared
• Terminate with 120 Ω resistors at both ends
• Default speed: 19200 baud, set in WebConfig

3. Field I/O

• Voltage inputs: L1, L2, L3, N, PE
• CTs: CT1–CT3 (1 V or 333 mV)
• Relays: dry contact, driven by internal logic or Modbus
• Buttons / LEDs: wired to MCU, mapped in firmware/UI

7.3 ESPHome Minimal Config (Enable Modbus + Import ENM Package)

uart:
  id: uart1
  tx_pin: 17
  rx_pin: 16
  baud_rate: 19200
  stop_bits: 1

modbus:
  id: rtu_bus
  uart_id: uart1

modbus_controller:
  - id: enm223_1
    address: 4
    modbus_id: rtu_bus
    update_interval: 1s

packages:
  enm223_1:
    url: https://github.com/isystemsautomation/HOMEMASTER
    ref: main
    files:
      - path: ENM-223-R1/Firmware/default_enm_223_r1_plc.yaml
        vars:
          enm_id: enm223_1
          enm_address: 4
          enm_prefix: "ENM #1"

7.4 Entities Exposed by the Package

Binary Sensors

• Relay states
• Button presses
• LED status
• Alarm conditions (Alarm / Warning / Event)

Sensors

• Urms, Irms L1/L2/L3
• Power (P, Q, S) totals
• Frequency, PF, Angle
• Energies: kWh, kvarh, kVAh (active/reactive/apparent)

Switches

• Relay 1/2 (Modbus coil 600/601)
• Acknowledge coils 610–613
• Override controls (force override toggle, hold-style)

Numbers (Optional)

• Sample interval
• Calibration gains (Ugain / Igain)

7.6 Using Your MiniPLC YAML with ENM

1. Keep existing uart: and modbus: blocks
2. Add the packages: block (as shown) and set enm_address from WebConfig
3. Flash the controller — ESPHome discovers all sensors/entities automatically
4. Add HA dashboard cards and switches for relay, override, and ack actions

7.7 Home Assistant Setup & Automations

• Go to: Settings → Devices & Services → ESPHome → Add by hostname or IP
• Dashboard auto-discovers:
  • Energies (for HA Energy view)
  • Relays, buttons, LEDs
  • Alarm states
• You can create:
  • Energy Dashboard source: VAh Total or AP Total
  • Automation:

8. Programming & Customization

8.1 Supported Languages

• MicroPython
• C/C++
• Arduino IDE

8.2 Flashing via USB-C

1. Connect USB-C to your PC.
2. Enter boot/flash mode if required.
3. Upload the provided firmware/source.

Boot/Reset combinations:

• Buttons 1 + 2 → forces the module into BOOT mode
• Buttons 3 + 4 → triggers a hardware RESET

These combinations are handled in hardware. Use them when flashing or manually rebooting the module.

🧭 Button layout reference:

8.3 Arduino IDE Setup

• Board Profile: Generic RP2350
• Flash Size: 2MB (Sketch: 1MB, FS: 1MB)
• Recommended Libraries:

#include <Arduino.h>
#include <SPI.h>
#include <SimpleWebSerial.h>
#include <Arduino_JSON.h>
#include <LittleFS.h>
#include <math.h>
#include <limits>

• Pin Notes:
  • Buttons: GPIO22–25
  • LEDs: GPIO18–21
  • RS-485: MAX485, DE/RE control over TX
  • USB: native, no UART bridge

8.4 Firmware Updates

• Upload via USB-C using Arduino IDE or PlatformIO
• Enter boot mode (Buttons 1 + 2)
• Upload default_enm_223_r1.ino from /firmware/
• Configuration is preserved (stored in LittleFS)
• Energy counters are safe (stored in FRAM)

9. Maintenance & Troubleshooting

10. Open Source & Licensing

11. Downloads

The following key project resources are included in this repository:

• 🧠 Firmware (Arduino/PlatformIO)
  firmware/default_enm_223_r1.ino
  Core firmware implementing Modbus RTU, alarm logic, relays, LED control, overrides, and WebConfig support.

• 🧰 WebConfig Tool
  tools/ConfigToolPage.html
  HTML-based USB Web Serial interface for live configuration, calibration, alarm setup, and logic assignment.

• 🖼 Images & UI Diagrams
  Images/
  Contains front-panel photos, system diagrams, wiring illustrations, and screenshots from WebConfig UI.

• 📐 Hardware Schematics
  Schematics/
  Includes PDF schematics for Field Board and MCU Board — ideal for developers, reviewers, or third-party modders.

• 📄 Datasheets & Manuals
  ENM-223-R1 Datasheet.pdf
  Covers full electrical and mechanical specs, terminal layout, block diagram, and pinout.

• 📦 ESPHome YAML Templates
  ENM223R1_ESPHome_Integration_Guide.md
  Ready-to-use packages: block for ESPHome controllers, with sensors, relays, alarms, override logic, and Home Assistant tips.

🔁 Latest releases can also be found in the Releases tab or in the Firmware/ directory.

12. Support

If you need help using or configuring the ENM‑223‑R1 module, the following support options are available:

🛠 Official Resources

• 🧰 WebConfig Tool (USB-C)
  Configure the module directly from your browser — no drivers or software required.

• 📘 Official Support Portal
  Includes setup guides, firmware help, diagnostics, and contact form.

📡 Community & Updates

• 🔧 Hackster Projects — System integration, code samples, wiring
• 📺 YouTube Channel — Module demos, walkthroughs, and tutorials
• 💬 Reddit Community — Questions, answers, contributions
• 📸 Instagram — Visual updates and field applications