The S4 Group Open: BACnet-N2 Router

Making legacy systems new again


One shopping mall


Manchester, Connecticut


1,000,000 Sq. Ft.


March 23, 2015


Decommissioned with full BACnet transition

Leveraging Legacy Systems for Future-Focused Projects

Years ago, GGP began a process of reinvesting in its mall properties around the country, making their operational technology systems more operationally efficient and capable of handling the bandwidth and energy usage demands of today and tomorrow. In this particular segment of the redevelopment process, GGP focused on The Shoppes at Buckland Hills Mall serving the Hartford area with approximately 140 shops and restaurants.

The problem

The OT backbone of the property was a legacy Johnson Controls Metasys BAS system. With the retrofitting project, GGP wanted to integrate the Metasys system with the new enterprise level monitoring, control and analytics engine. OTI was the Master Systems Integrator on the job and we brought in the S4 Group for their expertise with the Metasys system.

The technology solution

OTI and S4 decided on the S4 Open: BACnet-N2 router to manage each of the Metasys N2 field busses connected to supervisory controllers to pick up the field bus controllers and points and bring them to the enterprise level management solution that OTI was developing.

The plan was to have each N2 router model the Metasys N2 controllers and points and virtual BACnet devices. This allowed complete flexibility in choosing the appropriate head-end systems to provide accurate control and monitoring of the Johnson system.

Products used:

  • Five S4 Open: BACnet-N2 router appliances, sized appropriately for each N2 network.
  • The S4 Open Management Console software.
  • Five proprietary N1 NCM network level controllers.
  • Legacy Metasys Operator workstation with N2 commissioning and configuration tools.
  • Legacy N2 field networks of various HVAC application-specific control units and lighting controls.
  • Tridium JACE platform hosting the new head-end functions.


The legacy system was been integrated with the new energy and facilities management front-end, which features enhanced UI and analytics. With the S4 Open: BACnet-N2 router the legacy systems can be monitored from anywhere there is an internet connection with the ability to adjust set points and schedules remotely as well.

Since component parts of the legacy system were maintained, the retrofit project cost a fraction of a full rip and replace operation. The S4 Group solution prolonged the useful life of the legacy N2 field equipment and OTI has built on this success throughout its ongoing integration and service relationship with General Growth Properties. Implementing this solution allowed OTI to use what was available in the building at the time, and set the stage for a more comprehensive upgrade when budget and project plans allowed. Since the S4 Open: BACnet-N2 solution was integrated in The Shoppes at Buckland Hills Mall, the N2 routers have been decommissioned to make way for a full BACnet upgrade, which is the outcome everyone was working toward.