The BASrouter series is one of our most popular products because it provides a low-cost, reliable, and easy-to-configure solution for routing between BACnet/IP, BACnet Ethernet, and BACnet MS/TP networks. Its compact design and built-in diagnostics make it a go-to tool for system integrators commissioning or troubleshooting building automation systems. Based on feedback we've received from customers who use the BASrouter, we've developed an FAQ to address the most common topics system integrators and engineers encounter in the field—from bidirectional BACnet/IP and MS/TP routing to proper termination, placement, and configuration. Whether you’re commissioning a simple trunk or planning a larger, scalable architecture, these answers are designed to clarify how BASrouters work and how to install them correctly.
I can route from BACnet/IP → BACnet MS/TP, but can I route from BACnet MS/TP → BACnet/IP?
Yes, the BASrouter operates at the BACnet network layer, which allows it to route traffic in both directions between BACnet/IP and BACnet MS/TP networks. Devices on either side can initiate communication with devices on the other side as long as routing is configured correctly.
- The BASrouter supports stand alone routing between BACnet/IP, BACnet MS/TP, and BACnet Ethernet, with no directional restrictions.
- MS/TP devices can be discovered, read from, and written to by BACnet/IP clients, and MS/TP devices themselves can initiate BACnet services that are routed to the IP network.
In practice, this means:
- BACnet/IP workstations can read from and write to MS/TP devices.
- MS/TP controllers can send alarms, trends, and COVs upstream to IP supervisory systems.
Do I need specific configuration to connect end devices?
No special or proprietary configuration is required to connect devices to a BASrouter, beyond standard BACnet settings. Each MS/TP device must simply have:
- A unique BACnet device instance
- A unique MS/TP MAC address
- A matching MS/TP baud rate
- A correctly assigned BACnet network number
Capabilities vary by model:
- BASrouter/Portable BASrouter support MS/TP devices.
- BASrouterSX adds MS/TP slave proxy, auto discovery, and backbone routing for larger systems.
Where can I install a BASrouter on an MS/TP bus?
A BASrouter can be installed at the end or in the middle of an MS/TP trunk—termination settings are the key consideration. Use end of line Installation when the BASrouter is physically at one end of the MS/TP trunk. Use mid-span (middle of the bus) installation when the BASrouter is installed somewhere between other controllers.
The process varies by model.
For the BASRT-B EOL termination and bias are set via internal jumpers.
- End of Line Installation
- Enable EOL termination via the termination jumper inside the BASrouter.
- Leave bias enabled.
- Ensure the opposite end of the trunk has the only other EOL termination.
- Middle of the Bus installation
- Disable (remove) the EOL termination jumper.
- Bias may stay enabled or disabled depending on how biasing is handled elsewhere on the segment.
- Add termination to the trunk at the end devices.
For the BASRTSX-B EOL termination and bias are set via an external DIP switch.
- End of Line Installation
- Enable End of Line (EOL) termination using the front DIP switch.
- Enable bias (also via DIP switch).
- Verify that only one device on the other end of trunk has EOL termination enabled.
- Mid Span (Middle of Bus) Installation
- Disable EOL termination.
- Disable Bias via the DIP switch. If required, biasing is handled elsewhere on the segment.
- Add termination points at the two end devices.
The BASRTP-B does not provide any failsafe bias or EOL termination to the EIA-485 bus and can be inserted anywhere on the MS/TP segment.
| Installation | BASRT-B | BASrouterSX |
| End of MS/TP bus | Enable EOL jumper | Enable DIP switch termination |
| Middle of MS/TP bus | Remove EOL jumper | Disable DIP switch termination |
| Adjustment method | Internal jumpers | Front DIP switches |
| Ease of change | Requires enclosure access | Tool free |
Additional Information
BASrouters provide flexible, bidirectional BACnet routing with minimal configuration effort. Whether you’re adding IP access to an existing MS/TP network or designing a larger, segmented architecture, proper addressing and termination are all you need to get started.
