BACnet Router

A Versatile Interoperability Solution

Sierra Monitor's BACnet Router (FS-ROUTER-BAC) product offers a complete BACnet internetworking solution for BACnet/IP, BACnet Ethernet, and BACnet MS/TP networks, while also providing a secure connection to the cloud.

Multiple BACnet routing connections can be established:

  • BACnet MS/TP to BACnet/IP
  • BACnet MS/TP to BACnet Ethernet
  • BACnet MS/TP to BACnet MS/TP
  • BACnet/IP to BACnet/IP
  • BACnet/IP to BACnet Ethernet

The FieldServer BACnet Router is available in two models: the dual-port version and the single-port version.

Accessing the BACnet Router Through FieldPoP

Enjoy the benefits of the cloud connectivity through FieldPoP™. The BACnet Router is FieldPoP-enabled, meaning all BACnet Routers can be registered to FieldPoP, Sierra Monitor’s device cloud for the IIoT.

The FieldPoP web interface lets users remotely access, in a secure fashion, the FS-GUI and configuration web applications that are available locally on the BACnet Router. These applications offer functionality for configuration, monitoring, logging, security, diagnostics, and updates.

Learn more about FieldServer and FieldPoP capabilities »

Innovative Features

The dual-port BACnet Router has two RS-485 ports, enabling connection to up to 64 BACnet devices without the use of additional line drivers. Using a BACnet router frees up valuable RS-485 ports on expensive BACnet Controllers and reduces the cost of connecting BACnet MS/TP devices to a BACnet/IP backbone. Compared to single-port BACnet routers, our dual-port BACnet router can reduce the cost of device connectivity or double the speed of connected devices (half the response time).

As our entry-level and cost-effective BACnet solution, the single-port BACnet Router has one RS-485 port, enabling connection to up to 32 BACnet devices without the use of additional line drivers.

DeviceFind™, our unique discovery feature, allows the integrator to discover all the BACnet devices connected to the router with one push of a button, minimizing time required for successful commissioning. Complementing this feature is our diagnostic FieldServer Toolbox, which allows the user or integrator to view the status of and diagnose all the routers on the network.

Easy to Install & Use

Our BACnet Router's one page, set-and-forget configuration and unique network discovery capabilities minimize the integrator's installation time. The fully compliant, top quality BACnet stack helps reduce troubleshooting time. An MDIX module makes it possible to use any Ethernet cable for commissioning and installation. DHCP automatically obtains IP settings from your network.

The BACnet Router includes NAT support with a secondary BACnet/IP connection for routing between public and private networks. A BACnet Broadcast Management Device (BBMD) allows for connection between different subnets. Familiar, web-based configuration makes the system easy to use.

Certifications & Approvals

Sierra Monitor's BACnet Router is the first standalone device in the industry to carry the BTL (BACnet Testing Laboratories) mark. BTL certification ensures the highest standard of BACnet integration and assures users that they are utilizing a high-quality BACnet product. The BTL mark indicates that our router has passed a series of rigorous independent laboratory testing and verifies that the product fully implements the BACnet features claimed. In addition, the BACnet Router is RoHS compliant, TUV approved to UL-916, and CSA, CE and FCC approved.

BACnet Router

  • FieldPoP Device Cloud support: Register your BACnet Router to the FieldPoP interface for remote access to local applications, configuration, and device management
  • DeviceFind™: Minimize commissioning time by automatically discovering all BACnet devices connected to the router with a push of a button
  • BTL Certification: Most compliant and highest quality BACnet stack enables interoperability and reduces troubleshooting time
  • Dual RS-485 Port Option: Results in lowest cost per connected device or highest performance (response time) per connected device
  • Easy Configuration with Discovery: One page set and forget configuration along with unique network discover capability minimizes the integrator's installation time.

Specifications for the BACnet Router

Model Numbers

  • FS-ROUTER-BAC: 2 Serial Ports
  • FS-ROUTER-BAC1: 1 Serial Port


  • Serial RS-485
    • Galvanic isolation
    • Baud: 9600, 19200, 38400, 57600, 76800, 115200
  • Ethernet
    • 10/100 BaseT
    • MDIX
    • DHCP


  • Operating Temperature: -40o to 167oF (-40o to 75oC)
  • Relative Humidity: 5-90% RH non-condensing

Power Requirements

  • 9-30 VDC or 12-24 VAC
  • Current draw @ 12V: 240 mA

Physical Dimensions

  • 4.5 x 2.9 x 1.6 in. (11.5 x 7.4 x 4.1 cm)
  • 0.4 lb (0.2 Kg)


  • Web Configuration
  • Toolbox diagnostic utility
  • Table, Wall mount
  • DIN rail mount included


  • RoHS Compliant
  • TUV approved to UL-916, EN 60950-1
  • EN 50491-3
  • CSA C22.2 standards
  • BTL Certitication, Rev. 12
  • GOST-R Certified
  • CE and FCC

Protocol Drivers

The BACnet Router (FS-Router-BAC) from Sierra Monitor supports the full suite of BACnet protocols and provides internetworking across the protocols:


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Use Cases for the BACnet Router

There are several control networking, building automation, and building management scenarios where using a BACnet Router is appropriate. Here are some common use cases that a system integrator may encounter in the field that can be addressed by using Sierra Monitor's FieldServer BACnet Router.

1. How to Connect a Slower MS/TP Device

Even though most BACnet MS/TP devices run at 38,400 baud, integrators often have to connect devices that run at slower speeds, such as 9,600 or 19,200 baud, to the 38,400 baud trunk.

The FieldServer BACnet Router can connect low-speed MS/TP devices on one of its serial ports to higher speed devices (such as those using 38,400 baud) on its second serial port. One of the caveats that must be noted is that the low-speed device needs to be a Master that responds to “Who Is" commands.

Connecting to a slower MS/TP device with the FieldServer BACnet Router

2. How to Connect Remote MS/TP Trunks

Some large facilities, like a school or business campus, may have multiple buildings, each with many BACnet MS/TP devices. Connecting these disparate building-level BACnet segments using RS-485 technology is expensive because the long distances require line drivers to maintain communication integrity. The other alternative is to use an IP network to connect the different MS/TP based network segments. However, that typically requires adding BACnet/IP based controllers to each segment.

Using FieldServer BACnet Routers is an elegant solution to this problem. Each segment uses a FieldServer BACnet router to communicate with the other segment over BACnet/IP. The IP protocol runs over the LAN (local area network) or WAN (wide area network) depending on the physical locations of the buildings.

Managing a multi-trunk MS/TP network with the FieldServer BACnet Router

3. How to Connect 64 Devices to My Network

Facilities use BACnet routers to connect BACnet MS/TP devices to an IP backbone. Large facilities often have a large number of MS/TP devices and therefore have to deploy multiple BACnet routers, because typical BACnet routers usually have a single serial port and connect up to 32 MS/TP devices. The cost of connecting MS/TP to IP can thus add up.

The FieldServer BACnet Router has two serial ports, and therefore a single FieldServer BACnet Router can connect 64 devices instead of 32. In a large network, this is a cost-effective approach as it can reduce the number of required routers by a factor of two. The availability of two ports on the router also has performance advantages relative to single-port routers. For example, even if there are only 20 devices to be connected, with a two-port router, each port can take 10 devices versus the alternative of all 20 devices on the one port of a single-port router. With just half the number of devices on each port relative to a single-port router, a two-port router doubles the responsiveness of each connected device.

Connecting up to 64 devices with the FieldServer BACnet Router

4. How to Connect Legacy Ethernet Devices

Even though most devices or controllers that ship today support either BACnet MS/TP or BACnet/IP or both, many buildings have older devices and controllers based on the BACnet Ethernet standard that are still functioning and providing value. However, it is necessary to integrate these into a common BACnet/IP backbone for unified management. Also, BACnet Ethernet does not support BBMD – which is a key building block of a modern multi-site management framework. Of course, one could rip and replace the legacy BACnet Ethernet controllers, but that is an expensive option.

A better solution is to use the FieldServer BACnet Router to connect legacy BACnet Ethernet devices and controllers to the modern BACnet/IP backbone. The FieldServer BACnet router, which supports BBMD, in effect, acts as a proxy for the legacy BACnet Ethernet devices. The router's one page, set-and-forget configuration and unique network discovery capabilities also minimize the integrator's installation time.

Connecting to legacy Ethernet devices with the FieldServer BACnet Router

5. How to Manage a Multi-Trunk MS/TP Network

There are instances where BACnet MS/TP devices are in different buildings behind firewalls. However, the facilities manager needs to overview and manage all the devices as one unified network, from one front-end system, without compromising network security. One option is to ensure that each segment or trunk uses only BBMD-capable BACnet controllers. However, this adds cost.

The FieldServer BACnet Router is a cost-effective alternative to connecting different MS/TP segments behind firewalls into one common logical network that can be managed from a single front-end system. BACnet BBMD uses broadcasts to work well with firewalls and IP routers. It also allows for connection between different subnets.

Managing a multi-trunk MS/TP network with the FieldServer BACnet Router

How to Purchase the BACnet Router

There are a number of ways to purchase the BACnet Router:

Find an Online Distributor

A number of our authorized online distributors around the world carry the BACnet Router:

Contact Us

You can directly contact us to receive a quote: