# Introduction for FCU Control.

## Introduction

The RFTC-3 device is designed to control 2- and 4-pipe fan coils, and other HVAC equipment. It is equipped with a range of features that enable comprehensive and efficient climate control:

* **Fan Speed Relays**: 3x relays (LOW, MEDIUM, HIGH), 2x relays for HEATING/COOLING mode; relay behavior can be configured.
* **Analog Outputs**: 2x 0–10V analog outputs for proportional valve of fan control.
* **Inputs for Detectors**: 2x inputs for connecting wired detectors (magnetic door/window contacts).
* **External Sensor**: 1x input for external temperature sensor (TC/TZ).
* **Built-in Sensors**: Digital temperature and humidity sensor, proximity sensor for display backlight activation, ambient light sensor for automatic display brightness adjustment.
* **Display**: VA/TN LCD with 8 capacitive touch backlit buttons.
* **Connections**: Tool-free angled terminals for easy wiring; Wi-Fi for parameter configuration (via web browser) and connection to [iNELS.Cloud](http://iNELS.Cloud), iNELS APP, and HRS software through MQTT protocol.
* **Communication**: iNELS RFIO2 for wireless communication with iNELS Wireless devices; Modbus RTU for connection to HVAC equipment and supervisory systems.
* **Power Supply**: 110–230V AC.
* **Design**: Available in black or white; housing suitable for EU/BS mounting boxes with 60 mm screw spacing; customizable design (button functions, icons, logo) via [icons.inels.com](https://icons.inels.com/).

The **RFTC web interface** is a tool for managing and monitoring your RFTC device directly from your browser. This modern approach to climate control gives you easy access to all necessary functions and settings for optimizing temperature, ventilation, and other environmental parameters. In this guide, we’ll walk you step by step through the RFTC web interface and show you how to fully configure and manage your device. From basic settings to advanced features, you'll have full control over your climate management system. Let’s begin by learning how to use the RFTC web interface to effectively configure and manage your device, ensuring optimal comfort and environmental control in your space.


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