A public service building was an ideal test site
When the S4IS BACnet N2 integration development was nearing completion, S4 Integration Solutions (S4IS) issued a call for potential Beta test sites. For multiple reasons, it found one in Sharer Tech Inc.’s project with Oswego County, New York’s Public Service Building:
- Sharer Tech’s 14+ years relationship with Oswego County facilitated a working relationship conducive to supporting the Beta test.
- The relationship between S4IS and Sharer Tech became very strategic as more details about the site were learned.
- With success, there was potential for future business, expanding beyond the Beta test.
Oswego County Department of Facilities and Technology (buildings and grounds) in Central New York State includes a team that is responsible for all the buildings the county owns and operates. The building chosen for retrofit and Beta testing was the County Public Safety Building (Jail).
Oswego County’s population was 117,525, as of the 2020 United States census. Its name derives from a Mohawk-language word meaning ‘the pouring out place’, referring to the point at which the Oswego River feeds into Lake Ontario at the northern edge of the county in the city of Oswego.
Full access to N2 devices was a must
Oswego County was looking for a solution to replace its aging Johnson Controls NAEs (Network Automation Engine) while maintaining full access to the N2 devices. The team also needed access to the controllers on the trunk to allow system operators to use the JCI Metasys HVAC Pro utility for programming remotely. They required a way for the system operators to bring the controllers into their new Niagara server (provided by Sharer Tech) over BACnet, while still allowing for remote programming of the N2 controllers.
Other project requirements included:
- Converting the system seamlessly with minimal downtime, as this is at a corrections facility occupied 24/7;
- Running the NAE fully while the change over to the Niagara server took place with a goal for zero down time; and
- Adhering to all facility physical security and controlled access regulations.
Eight buildings and a mixture of control systems
The Oswego County complex has eight buildings, but only one–the jail–has N2 in it. This building has two N2 systems: One in the Beta project, and one that has the rest of the jail’s heat pumps on it. The other buildings are mixture of Trane, Automated Logic, and Metasys BACnet.
The Beta test focused on one Metasys network that was complex enough to exercise the S4IS system but in a non-critical area that would allow the test process to be successful. The major components of the project were:
- Johnson Controls Metasys server (ADX)
- NAE
- N2 field bus with 17 N2 devices
- Niagara server station setup for BACnet-IP
- S4-BACnet N2 Integration
- Required network infrastructure and power provided by Oswego County
The legacy BAS was a JCI Metasys® system comprised of the Metasys server, numerous NAEs, and multiple RS-485 com buses connecting the NAEs to field controllers. Some field buses were BACnet MSTP, and others were N2 trunks.
Several approaches were considered
The initial approach was to convert the entire trunk to BACnet controllers, at a massive cost to the customer. After that was declined, Sharer Tech considered placing JACEs in place of the NAEs, then having separate dedicated computers running HVAC Pro connected to them to remote in and configure controllers once the trunk was disabled within the JACE. It became overly complicated for the customer, and that plan was scrapped.
They also considered using a Niagara Tridium JACE, Serial to ethernet converters, and Mini PCs to build a system that could still provide the necessary connections to the field controllers from remote locations. This quickly became too complex and required a significant amount of custom code that would need to be maintained
The S4IS BACnet N2 Integration to the rescue
The first step in the integration project was to verify that the N2 bus was electrically in spec. Sharer Tech uses the S Squared Innovations S2USB485 as their standard test and verification tool because it doubles as a USB to RS-485 (N2) adapter, which supports the HVAC Pro and GX9100 configuration and commissioning tools to interrogate, recommission, and upload UNTs, VMAs, VAV, and DX-9100 controllers.
As mentioned earlier, the conversion had to happen with zero down time. The Upstream N2 Interface enabled Oswego County’s requirement to keep the existing legacy Metasys head end and server systems fully functional during the conversion process. The S4IS BACnet N2 Integration system was completely transparent to the NAE.
The integration of the NAE, the S4IS user interface, and the Tridium system through the BACnet priority array enabled all systems to stay synchronized and allowed the Sharer Tech team to determine which system had control of each point and gracefully transition full control to the Tridium system.
Successful integration sets the stage for follow-on integrations
The Beta test was a success, and the integration has been moved to a production installation.
The NAE is still connected to the Upstream interface and is co-existing with the Tridium server. The plan is to keep the current Metasys system connected and fully functional utilizing the S4IS Upstream N2 Interface while at the same time bringing the Niagara system online. This will give the operators time to ease into using Tridium Niagara system while being able to fall back to the Metasys system if need be. When controlled by either system, any adjustments or overrides will show in either system. If an override in the Metasys has been issued, it will show in override on the Niagara server as well.
Since the S4IS BACnet N2 Integration is publishing data from the Legacy N2 devices as BACnet IP, the site is moving toward an open and future-proofed environment. Any value-added applications required by the site in the future can utilize the same BACnet IP data stream.
A smooth conversion from JCI Metasys to Tridium Niagara system. One S4IS system update was required to fix a problem with the system drive filling up to capacity. That update resolved the issue, and it has not recurred after an extensive amount of running time. The customer wasn’t even aware of the issue because of the quick support provided by S4IS during the Beta testing.
A smoother migration from Metasys to Niagara control systems than could have been accomplished by any other method or technology.
Jamie Sharer, president and technical team lead, Sharer Tech, Inc., notes:
” Even though the JACEs can communicate with the N2 bus, they don’t have the ability to perform the critical passthrough function to remotely program N2 controllers with HVAC Pro software. This is where the S4IS-BACnet N2 Integration became essential. We were able to not only to replace the NAE with the S4IS system, but we also didn’t have to add another JACE to the system, as we brought the controllers in through BACnet-IP directly to the server.”
This successful integration sets the stage for follow-on integrations at the jail facility and throughout the county. While the NAEs remain in place for now, they are planning to replace them with JACEs to keep up with the new IT Cybersecurity standards. The NAEs run a no-longer-supported operating system that doesn’t comply with the ever-evolving network security requirements.
Ultimately, all Oswego County and Sharer Tech goals were met:
- Absolutely no down time experienced in the legacy N2 system and no HVAC equipment going down during the conversion.
- Saved the county from the immediate cost of having to commit to a large capital project to replace the N2 devices with new BACnet controllers. Because it’s a jail and is occupied 24/7, projects of this nature typically incur extra costs to keep the mechanical equipment fully operational. Those costs were avoided.
- During the Beta test process, Sharer Tech identified the need for a replacement for the Metasys Passthrough capability.
At the S4IS site, learn more about the S4IS BACnet N2 Integration system.
