The Johnson Controls Metasys Building Automation System (BAS) has continued to improve over several product generations. The Field Equipment Controller (FEC) family of this BAS includes technological advancements in both hardware and software, compared to previous versions of controller products. This enables more advanced control and communication. The Metasys General Purpose Application Controller (CGM) and VAV Box Controllers (CVMs) are the first models of a new, modernized family of equipment controllers which integrate within the web-based Metasys system. The CGM and CVM controllers are versatile equipment controllers designed to monitor, control, and integrate a wide variety of HVAC and other building equipment.
Many of the N2 equipment controller devices, including controllers and accessories, introduced with the first Metasys generation still operate on customer sites, but their technology represents a particular window in time. The legacy tools for N2 are only supported on 32 bit platforms.
Direct replacement and repair of parts becomes impossible to manufacture as component sources move their production to more advanced products. In addition to hardware obsolescence, many of the configuration tools and commissioning interface hardware required to configure systems using legacy controllers are no longer supported on modern laptop configurations and operating systems. Rewriting software for these tools and deriving new interface hardware is neither cost effective nor consistent with the current Johnson Controls platform consolidation initiatives.
The Controller Configuration Tool (CCT) enables equipment controllers (Metasys/FX) to be configured for either the BACnet MS/TP or the N2 communications protocol.
The FEC family includes Advanced Application Field Equipment Controllers (FACs), Field Equipment Controllers (FECs), and Variable Air Volume Modular Assembly Controllers (VMAs). These models are referred to in this document from this point forward as FEC.
The CGM, CVM, and FEC family controllers are N2-capable equipment controllers. Customers with legacy N2 controllers installed in their building can use N2-capable equipment controllers, because they enable cost-effective replacement and expansion of their installed base of controllers.
These same customers also benefit from the more modern equipment controller technology, that includes state-based control, event-driven logic, and automatic tuning. In addition, the ability to switch the N2-capable equipment controllers back to BACnet MS/TP provides customers with a cost-effective upgrade path to a modern, higher performance field bus technology.
The modernization guide is intended to help you choose and implement the most appropriate strategy for your customer. Also, this guide describes the key installation and configuration differences to help you prevent, minimize, and overcome installation and configuration challenges.