Johnson Controls Metasys
Running on Borrowed Time?
The N2 bus isn't getting any younger. If you're running legacy Metasys — especially N2-based systems — you're facing a shrinking window for a clean upgrade path.
Talk to a JCI SpecialistStill Running N2 or Legacy Metasys?
Johnson Controls Metasys has been one of the most widely deployed BMS platforms in commercial buildings. If your building was built or renovated between 1990 and 2015, there's a good chance you have some flavor of Metasys running your HVAC.
The problem? JCI has moved on to newer platforms, and support for legacy systems is becoming increasingly difficult to find.
The N2 Problem
- • N2 is a proprietary serial bus — no modern devices speak it
- • Controllers are failing with no direct replacements
- • Finding technicians who understand N2 is increasingly difficult
The Obsolescence Problem
- • Legacy NAEs running outdated firmware
- • NCM/NCE controllers no longer manufactured
- • ADS/ADX servers running on Windows XP or 7
The Vendor Lock-in Problem
- • JCI often pushes full system replacement
- • Quotes for "upgrades" are really new installations
- • Proprietary tools and licensing create barriers
We Know Metasys Inside and Out
We've worked on every generation of Metasys — from ancient Companion systems to current NAE/NIE platforms.
Controllers
- DX-9100 — The workhorse unitary controller
- FX/FC Series — Field controllers
- CGM — Central plant controllers
- VMA — VAV modular assemblies
- TEC — Thermostat/zone controllers
Network Engines
- NAE35/45/55 — Network automation engines
- NCE25 — Network control engines
- NCM — Legacy network control modules
- NIE — Network integration engines
Protocols & Buses
Software
- ADS/ADX — Application & Data Server
- Metasys UI — Web-based interface
- SCT — System Configuration Tool
- GCL+/PCODE — Controller programming
Common Scenarios We Handle
N2 Bus Failing
Controllers dropping off the bus, communication errors, entire trunks going down. We can stabilize and plan migration.
NAE Needs Replacement
Old NAEs running outdated firmware or failing hardware. We can replace with new NAEs or migrate to Niagara.
Server Migration
ADS running on Windows XP? We can migrate to modern servers or transition to Niagara supervisor.
Vendor Independence
Want to break free from JCI's ecosystem? We can integrate your system with open platforms.
The N2-to-BACnet Challenge
The biggest headache with legacy Metasys is the N2 bus. It's a proprietary protocol that modern devices don't speak. Your options:
- → N2 Router — JCI's bridge to BACnet (if you can get one)
- → Niagara with N2 driver — Third-party integration option
- → Controller replacement — Swap N2 devices for BACnet
- → Hybrid approach — Migrate in phases as controllers fail
We've done all of these. The right approach depends on your building, budget, and timeline.
Upgrade Paths
Different situations call for different approaches. Here are the paths we typically recommend.
Stay in Metasys
Best for: Buildings committed to JCI ecosystem
- • Upgrade NAEs to current generation
- • Replace N2 controllers with BACnet equivalents
- • Migrate ADS to current Metasys UI
- • Maintain JCI support contract
Pros: Familiar platform, JCI support
Cons: Vendor lock-in, higher cost
Niagara Supervisor
Best for: Vendor independence + gradual migration
- • Niagara JACE/Supervisor on top of Metasys
- • Integrate via BACnet where available
- • N2 integration via drivers
- • Modern UI, alarming, trending
Pros: Open platform, phased approach
Cons: Two systems during transition
Full Migration
Best for: Complete system overhaul
- • Replace Metasys controllers entirely
- • Migrate to Niagara or other platform
- • Keep field devices where possible
- • Clean break from JCI
Pros: Clean slate, modern system
Cons: Higher upfront cost
Frequently Asked Questions
Can you work on Metasys without JCI involvement?
Yes. We're independent integrators with our own tools and expertise. We can program, troubleshoot, and upgrade Metasys systems without going through JCI — often at lower cost.
Is it possible to keep my N2 controllers running?
For now, yes. We can maintain N2 systems and source replacement controllers. But the supply is dwindling, and we recommend planning for migration. N2 is a dead end — the question is when, not if.
What about my programming and sequences?
We extract and document your existing logic before any migration. Metasys programming (PCODE, GCL, etc.) can be translated to modern platforms. You won't lose the customization your building depends on.
How long does a Metasys upgrade take?
Depends on scope. A Niagara overlay can be done in 4-8 weeks. Full N2-to-BACnet migration for a large building might take 3-6 months. We phase work to minimize disruption.
Can you help if I'm outside NYC?
Yes. We provide remote support nationwide using secure access infrastructure. Programming, troubleshooting, and commissioning can all happen remotely. We travel for hands-on work when needed.
Let's Talk About Your Metasys System
Whether you need emergency support, planning for migration, or just want to understand your options — we're here to help.
Schedule a Consultation