How healthy is your MS/TP network?

Tech tips MS/TP Visual BACnet
Top tech tips for managing MS/TP networks

This is why Visual BACnet has three diagnostic checks for MS/TP traffic.

VisualBACnet's MS/TP checks

I’m going to focus on the top two diagnostic checks: using “Average Token Round-Trip Time” and the “Standard Deviation of Token Round-Trip Time” to assess your MS/TP network. (Need help capturing an MS/TP file in Wireshark? Steve Karg can help you here!)

Average Token Round-Trip Time

The industry best-practice for Average Token Round-Trip Time in an MS/TP network is maximum 80ms. If this is the case in your network, the diagnostic check will pass. You will see a warning for the check if your average time is up to 2000ms, and a fail if it is any longer than that.

Long round-trip times usually indicate a high amount of traffic, and can also point to potential buffer overflow.

Clicking on the diagnostic check allows you to see how long each token pass took. Sorting by the maximum and mean times will give you some insights into which sources and destinations may be problematic.

Visual BACnet's MS/TP checks

Standard Deviation of Token Round-trip Time

The Standard Deviation of Token Round-trip Time shows how much the length of a token round-trip varies. While it is normal for a round-trip to be slightly longer approximately every 50 trips (because the system is polling for new devices), it is unusual for round-trip time to vary dramatically. If this is the case, there is quite likely something interrupting the token and potentially a master being skipped in the token passing.

Drilling into the diagnostic check, you can sort by standard deviation to see which devices are the worst offenders and start your troubleshooting here.


It is important to look at these two diagnostic checks together. A long average round-trip time with large standard deviation can point to big problems and disruptions in your network.

Conversely, a long round-trip time with little variation may mean that although the system is not optimal, it is working consistently.

Drilling down into these diagnostic checks also shows you each token pass that occurred during the capture. If you notice a source device passing the token to more than one destination regularly, that means the destination device (next master of the source) did not receive the token at some point and was skipped. The problem may be in the destination device itself or the wiring between the source and destination devices.

While each system is different, our diagnostic checks can help you understand what is happening in your system and what is causing your problems.

Recent Blog Posts

Over the years, we’ve dug into solutions for the most common problems we see on BACnet networks: everything from MS/TP issues, to Global Who-Is broadcasts, duplications, and Circular Networks.

When I really think about it, I’m astounded by how much movement and change there is among companies in the building automation industry.

The world of IT does not look quite like it did 40, or even 30 years ago. 

June 12, 2018, Vancouver, BC – Vancouver-based Optigo Networks, the network connectivity, monitoring, and analytics company, has released a new report on the challenges and opportunities for BACnet in smart b

Not so long ago, Penn State had big network problems.

Think tons of network traffic, buildings dropping offline — that sort of thing.

Recent Projects

Penn State University Visual BACnet Site Monitoring Optigo Networks


When Tom Walker first started working at Penn State University four years ago, there were a lot of network issues. Buildings were dropping offline. Broadcast traffic was pushing 90,000 packets per hour. Walker was on the phone almost every single night because devices were down or had to be reset.


Torre Manacar Optigo Networks Optigo Connect Mexico City High-rise shopping centre


When MR Soluciones began work on Torre Manacar, they knew they needed a flexible and scalable network infrastructure to support a wide array of integrated systems. Optigo Networks was a natural fit for the massive project, designing a robust network at a competitive cost.



Short Pump Town Center, an upscale retail center, underwent a complete renovation in 2014. The flexibility of Optigo Networks’ solution meant the retail center’s unknown final design was not a barrier to placing IP surveillance equipment in the field.



Optigo Networks connected New York-based Boulevard Mall’s security surveillance devices in December 2015, using a Passive Daisy Chain topology.

Tech Support Team


One tech support team at a manufacturer purchased an account with Visual BACnet in April 2017, for technical problems around the world.

Aster Conservatory Green


The Aster Conservatory Green is a residential community comprising 352 residences across 24 low-rise buildings. The buildings use advanced surveillance and access control technology, including 40 HD video cameras and 60 FOB-access-tele-entry points for access control.



When Delta Building Automation (Australia) won the BMS Upgrade at 25 National Circuit for the Australian Trucking Association, they partnered with Optigo Networks to create a secure and robust Building Services Network (BSN). Optigo Connect more than delivered on this project with a scalable solution that restored the building network to perfection.

Optigo Connect Seattle Stadium


Optigo Connect offered a simple, cost-efficient solution for a premier Seattle-based stadium. Optigo Networks’ design improved the surveillance system to crystal clear perfection, made it dependable, and allowed the security system to scale with the addition of more than 40 16MP cameras.



Optigo Networks and Controlco offered a secure and scalable solution for four data centers’ HVAC and Access Control systems throughout the United States. Optigo Connect’s performance in the first data center was so impressive, the client asked that Optigo replicate the network design for three other data centers.



Energy analytics company BUENO Systems was working on a mall when the worst happened. The network failed and equipment failed to “ON,” which kept units running 24 hours a day. As it turns out, the mall’s network was overloaded and glitching before BUENO even deployed. It had been for a while. These latent issues were a ticking time bomb and would have resulted in a failure if any new devices were added to the network. Because it was BUENO’s device, though, they had to fix it. The only way to fix it was out of pocket.