Description
The iO HVAC Controls BAC-RTR is a dual port BACnet/IP to BACnet MS/TP router with a built-in Modbus gateway, giving integrators a single compact device to bridge IP-based BAS networks with RS-485 field devices. Its DIN-rail mountable metal enclosure makes it a natural fit for control panels, and it can be powered by a hardwired 12-24V AC/DC supply or directly through its mini USB port — useful for bench configuration or troubleshooting without pulling panel power.
On the network side, the BAC-RTR includes one 10/100 Mbps Ethernet port with auto-negotiation and auto-MDIX, plus two independent RS-485 connections supporting standard BACnet MS/TP baud rates from 9600 up to 115200 bps. Each RS-485 port includes DIP-switch-selectable 120Ω bus termination and 519Ω bus biasing, so techs can properly terminate and bias the MS/TP segment without needing external resistors. The RS-485 interface is 1500V isolated and protected against ESD (15kV air / 8kV contact), supporting up to 1/8 unit load per device and cable runs up to 3,937 ft. (2,952 ft. at 115200 bps).
Beyond standard BACnet functionality, the BAC-RTR offers a set of extended features aimed at improving MS/TP network performance and reliability: Auto and Forced baud rate detection, automatic AB line polarity correction, a “Fast Device” table for tuning timeouts on a per-device basis, and a Slave Proxy function that lets the router represent MS/TP slave devices (including those that don’t support the BACnet Who-Is service) to the rest of the BACnet network. A built-in packet capture tool — with normal, interval, and raw download formats — lets techs pull Wireshark-compatible captures directly from the router for network troubleshooting, without needing a separate protocol analyzer in the field.
Configuration is handled through a browser-based WebUI (default IP 192.168.100.1), with support for offline configuration and import/export of settings — so a system can be fully configured ahead of time and simply uploaded once on-site. A rescue upgrade mode built in plain HTML ensures the router stays recoverable even if a firmware upgrade to the main WebUI fails. The included Modbus gateway supports both single device and virtual device mapping modes, with an online point-test and read-group-test tool to verify Modbus register mapping before commissioning is complete.
Whether used as a straightforward BACnet router between an IP-based head end and MS/TP field devices, or as a combined BACnet/Modbus gateway on more complex jobs, the BAC-RTR is built to simplify commissioning, troubleshooting, and long-term network management for BAS integrators and HVAC controls contractors.
Features:
- Dual Port BACnet/IP to MS/TP Routing – One Ethernet port (10/100 Mbps) plus two independent RS-485 ports for flexible network topology
- Built-In Modbus Gateway – Supports single device and virtual device mapping modes with online point and read-group testing tools
- Flexible Power Options – Hardwired 12-24V AC/DC screw terminal or mini USB, ideal for both panel installs and bench setup
- DIN Rail Mountable Metal Enclosure – Compact 4.76″H x 2.95″W x 1.14″D footprint designed for control panel installation
- Selectable Termination & Biasing – DIP switches for 120Ω bus termination and 519Ω bus biasing on each RS-485 port — no external resistors needed
- Advanced MS/TP Tuning – Auto/Forced baud rate detection, AB line polarity correction, Fast Device timeout tuning, and Slave Proxy support for non-compliant MS/TP devices
- Built-In Packet Capture – On-device Wireshark-compatible packet capture (normal, interval, and raw formats) for field troubleshooting without extra tools
- Offline Configuration & Import/Export – Pre-configure the router without it on hand, then import settings on-site for fast commissioning
- Rescue Upgrade Mode – Plain-HTML recovery entry point ensures the router remains recoverable even after a failed firmware upgrade
- Robust ESD & Isolation Protection – 1500V isolated RS-485 interface with 15kV air / 8kV contact ESD protection
- Regulatory Compliance – CE Mark; CFR 47, Part 15 Class B











