Shelly Pro Modbus Add On

Device identification

• Device name: Shelly Pro Modbus Add-on RS485

• Device model: N/A

• Device SSID: N/A

• BLE Model ID: N/A

Short description

The Pro Modbus Add-on RS485 expands Shelly Pro devices into powerful professional automation components. By adding reliable RS485 communication, it enables seamless integration with BMS, EMS, SCADA, and professional automation systems through a widely adopted wired communication standard. Designed for long-distance, noise resistance communication, the Add-on unlocks new possibilities for commercial buildings, large residential installations, and renewable energy systems.

Pro Modbus Add-on with RS485 is compatible with Shelly Pro EM-50, Shelly Pro 3EM, Shelly Pro1 and Shelly Pro 2.The Pro Modbus Add-on attaches directly to the expansion port of the Shelly Pro devices, allows easy integration into building automation platforms, and energy management systems, and professional monitoring solutions.
The Pro Modbus Add-on with RS485 supports operation as both a Modbus client, enabling Shelly devices to read data from external meters and controllers, and Modbus server, allowing Shelly devices to share their own measurements and states with other systems.

Main features

• Connect directly to the Shelly Pro EM-50, Shelly Pro 3EM, Shelly Pro1 and Shelly Pro 2 expansion port for clean, compact, and secure installation

• Designed as a simple and intuitive expansion module, enabling fast integration into existing automation and monitoring systems without complex configuration

• Support operation as both a Modbus client and Modbus server, allowing flexible data exchange and system integration

• Support multi-device RS485 networks, allowing multiple devices to communicate on the same bus

• Uses standardized RS485 communication ensuring compatibility with BMS, EMS, SCADA, and professional automation platforms

• Provides reliable and stable communication, suitable or long cable runs and electrically demanding environments commonly found in commercial and building installations

Use cases

• Energy Monitoring
  With the Pro Modbus Add-on RS485, Shelly Pro EM devices become suitable for professional energy monitoring systems in commercial, commercial-residential, and multi-tenant buildings. The Add-on allows energy data to be delivered directly to BMS, EMS, SCADA dashboards through RS485 - a widely adopted professional communication standard.

• Building Automation System (BMS)
  The Pro Modbus Add-on RS485 enables Shelly Pro devices to integrate directly into Building Management Systems (BMS) used in commercial buildings, hotels, offices, and large residential installations. Through RS485, BMS controllers can reliably communicate with Shelly device to monitor electrical loads and operate building equipment.

• Professional Automation and Equipment Control
  The Pro Modbus Add-on RS485 allows Shelly Pro devices to participate in professional automation environments by communicating with PLC’s, motor controllers, and gateways over RS485. This expands Shelly’s capabilities to factories, workshops, and production-related facilities, while maintaining a flexible and compact automation approach.

• Renewable Energy Integration
  The Pro Modbus Add-on RS485 enables Shelly Pro devices to be seamlessly integrated into renewable energy systems such as solar PV installation, battery storage solution, microgrids, and hybrid energy setups. With RS485 connectivity, Shelly devices can communicate directly with solar inverters, charge controllers, and energy gateways that rely on robust wired communication.

• HVAC Integration

  The Pro Modbus Add-on RS485 enables Shelly Pro devices to integrate seamlessly HVAC systems that can use RS485 communication. Using the add-on, Shelly Pro devices can monitor HVAC operational data, control auxiliary equipment, and connect HVAC installations to building automation platforms through a reliable, long-distance wired interface.

Main applications

• Professional Automation and System integration (PLC Integration, process control, factory monitoring, etc.)

• BMS - Building Automation (HVAC Systems, Lightning control, etc.)

• EMS - Energy Management System (consumption tracking, billing and cost allocation, etc.)

• Renewable Energy and Smart grid (solar monitoring, battery storage, etc.)

• Professional Residential and Commercial automation (smart homes, mixed-use buildings, commercial spaces, etc.)

Device electrical interfaces

• RS485 GND

• RS485 communication lines A and B

Connectivity and protocols

• Modbus RS485

• Two modes capabilities

  • Client mode - includes JS interface and “Controller” functionality

  • Server mode - exports data from existing functional components

User interface

Inputs

-

Outputs

• LEDs (monocolor) indication:

  • RX – LED flashes when receiving data

  • TX – LED flashes when transmitting data

  • Power - red light indicator will be on if power supply is connected

Specifications

Basic wiring diagrams

Compliance

• Shelly Pro Modbus Add-on RS485 multilingual EU declaration of conformity 298 2026-06-16.pdf

• Shelly Pro Modbus Add-on RS485 UK PSTI ACT statement of compliance 298 2026-06-16.pdf

• Shelly Pro Modbus Add-on RS485 UKCA declaration of conformity 298 2026-06-16.pdf

Printed user guide

• Shelly Pro Modbus add-on multilingual printed user and safety guide.pdf