HONEYWELL FC-RUSIO-3224 Remote Universal I/O Module

Description

1. Core Overview & Positioning

2. Key Features & Functions

• Remote I/O Expansion:​ Acts as a satellite I/O unit, connecting to a master controller via a serial communication bus​ (C-Bus, RS-485). It adds 24 flexible, configurable I/O points to the system.
• Universal, Configurable I/O Channels:​ Like the main controllers, its I/O points are software-configurable. Each of the 24 points can be individually programmed in the engineering software to function as:
  • Analog Input (AI):​ 0-10V DC, 0-20mA, 4-20mA, RTD (Pt100, Pt1000, Ni1000), or potentiometer (0-1000Ω) input.
  • Digital Input (DI):​ Dry contact (volt-free) status input.
  • Analog Output (AO):​ 0-10V DC or 0-20mA output.
  • Digital Output (DO):​ Triac (for 24V AC loads) or relay output (for dry contact).
• No Independent Processing:​ Unlike a field controller (FC-TSKUNI), the RUSIO module does not execute control logic. It is a «dumb» I/O device. All I/O data is read from and written to by the master controller​ over the communication link. The master controller houses the control program.
• LED Status Indicators:​ Provides visual status for power, communication health, and I/O point activity.
• Compact, DIN-Rail Mountable:​ Designed for easy installation in electrical enclosures near the field devices.

3. Model Number Breakdown & Specifications

• I/O Capacity:​ 24 universal, software-configurable points.​ The exact mix is defined in software (e.g., could be 16 AI, 8 DO, or any combination).
• Communication Interface:​ Connects to the master controller via a serial bus:
  • C-Bus (Controller Bus):​ Honeywell’s high-speed, deterministic peer-to-peer network (up to 115.2 kbps). The primary network for Excel 5000 systems.
  • RS-485:​ Often supports standard serial protocols (like Modbus RTU) for integration with third-party systems or as an alternative link.
• Power Supply:​ Typically 24V AC or 24V DC​ (standard for building automation).
• Operating Temperature:​ 0°C to 50°C (32°F to 122°F).
• Mounting:​ Standard DIN-rail (TS35).
• Isolation:​ Channel-to-channel and channel-to-bus isolation for noise immunity.

4. System Integration & Architecture

• Master-Slave Architecture:​ The FC-RUSIO-3224 is a slave device​ on the C-Bus network. A master controller (e.g., an FC-TSKUNI-1624, FC-SMA, or FC-SD) polls it for input data and sends it output commands.
• Wiring:​ Field devices (sensors, actuators) are wired directly to the terminal blocks of the RUSIO module, which is installed locally near them. Only a single communication cable (and power) needs to run back to the main controller panel.
• Engineering Configuration:​ Configured within the same engineering software as the master controller (Honeywell CARE​ or Niagara Workbench). The steps are:
  1. Add the RUSIO module to the hardware configuration of the master controller’s station.
  2. Assign it a unique C-Bus address​ (set via DIP switches on the module).
  3. Configure each of the 24 points as AI, DI, AO, or DO, and define scaling, normal states, etc.
  4. The master controller’s application program then references these remote I/O points as if they were local.

• 5. Typical Applications
  

• Distributed Equipment Monitoring:​ Placing I/O near rooftop units (RTUs), fan coil units (FCUs), or heat pumps spread across a building to minimize conduit runs.
• Large Mechanical Rooms:​ Expanding I/O capacity for complex air handling units (AHUs) or chiller plants where the number of points exceeds the local controller’s capacity.
• Lighting Control Panels:​ Serving as the I/O interface for a bank of lighting relays and occupancy sensors in a remote electrical closet.
• Integration of Third-Party Equipment:​ Using the analog and digital I/O to interface with equipment that has only basic control terminals (e.g., a packaged chiller with alarm contacts and a start/stop terminal).