Communication protocol

SkyQ uses Modbus communication throughout — not BACnet. This is important for wiring decisions because Modbus has fewer device limitations on the bus and significantly faster discovery than BACnet MSTP.

The recommended baud rate is 57,600. This is pre-configured at the factory on all units ordered with a SkyQ option. If retrofitting an existing SEC controller, you must manually set the communication protocol to Modbus at 57,600 baud.

System bus topology

The NC2000 Network Controller sits at the top of the system and acts as the central hub. All other devices connect off the Modbus system bus that runs from the NC2000.

Single zone

The smart equipment rooftop unit connects directly to the system bus via the Modbus com card. NSA1000 wall sensors connect to the SA bus on the SEC controller — same as it has always been, no change required.

Multi-zone (smart equipment)

The Zone Q controller connects off the system bus. From the Zone Q, a single wire runs up to the smart equipment unit. The Zone Q then wires down to each zone damper (VC2000 controllers). This is a key wiring difference from Verasys — see the Zone Q migration note below.

Multi-zone (third-party units)

The M2000 controller replaces both the zone coordinator and zone logic in one device. Wire the M2000 to the system bus; it handles all zone control internally without needing a Zone Q.

Third-party BACnet devices

A BACnet Bridge device is required to tie third-party BACnet equipment into the Modbus system bus. This is an additional device in the wiring topology — it was not needed with Verasys.

Zone Q wiring — key difference from Verasys

This is the most important wiring change when migrating from Verasys to SkyQ:

How Verasys was wired (multi-zone)

System bus → Zone Coordinator → wire to smart equipment unit → wire down to first zone damper → daisy chain to remaining zones.

How SkyQ is wired (multi-zone)

System bus → Zone Q controller → single wire directly to smart equipment unit. The Zone Q also wires directly down to all zone dampers independently.

The migration step

Disconnect the wire that previously ran from the rooftop down to the first zone damper. Re-attach that wire to the Zone Q controller instead. Only one wire should run between the Zone Q and the smart equipment unit. The Zone Q can remain inside the building and wire directly to all zone dampers from there.

Wiring reuse when migrating

Wireless option

The TREE-COM Adapter provides wireless connectivity with a 2,000 ft line of sight range (up from 1,000 ft with Verasys). In real-world conditions with obstructions, 500–800 ft of effective range is still considered highly capable.

Wireless can eliminate significant wiring runs in difficult installations, saving both labor and material costs. Field trial testing has been described as excellent. The TREE-COM device is approximately hockey puck-sized.

Connection via Bluetooth is also available for service/commissioning use only — connect the 485-BT Service Tool to the NC2000 to create a Bluetooth signal for a mobile device.

Connection methods to NC2000

Hardware lineup

Photo	Device	Part	Purpose
	Network Controller 📄 Spec Sheet	NC2000	Ties system together; wired or wireless connection. Replaces Smart Building Hub.
	Smart Equipment Controls	SEC/SSE/UCB	Built-in controller on all smart equipment units from Sunline through Select (~2–50 ton).
	T1100 Thermostat	T1100	Two-stage thermostat; Modbus connected; for third-party single zone units.
	Zone Q Controller	Zone Q	Multi-zone with smart equipment units. Replaces Verasys Zone Coordinator.
	M2000 Controller	M2000	Third-party unit multi-zone control. Zoning logic built in — no Zone Q needed.
	M2000-FLX Controller	M2000-FLX	Flexible I/O — lighting, interlocks, ancillary controls.
	VC2000-BYP Controller	VC2000-BYP	Dedicated changeover bypass (COBP) damper control.
	VC2000 Controller	VC2000	Zone damper control; pressure dependent and independent. Supports remote actuator.
	TREE-COM Adapter	TREE-COM	Wireless adapter; 2,000 ft line of sight range.
	485-BT Service Tool	485-BT	USB wired connection to NC2000, or creates Bluetooth signal for mobile access.
	Service Panels	—	Houses controllers; optional touchscreen UI. Coming in next few months.

Verasys → SkyQ component map

Covers ~90–95% of typical applications. Existing wiring can be reused when replacing Verasys or earlier YCCS systems.

Zone Q wiring note

Key change when migrating: disconnect the wire from the rooftop to the first zone and connect it to the Zone Q controller instead. Zone Q then wires directly to the smart equipment unit with a single wire, then down to all zone dampers. NSA1000 sensors stay on the wall for single zone; multi-zone requires new wall sensors.

Platform availability

Apps are functionally complete — a few remaining details before app store release. Use desktop for new system setup, then any platform for ongoing use.

Software features

Floor plan / image view

Upload any image (floor plan, building photo) and drag-and-drop device icons. Color coding: blue = cooling, red = heating, green = satisfied. Create multiple screens for large buildings.

Smart Equipment integration

Full access to all SEC menus directly in SkyQ — replaces Go Temp Pro app. Dashboard replaces Circle of Comfort screen. Double-click graphic components to drill into settings.

Connection methods

• TCP/IP (wired network)
• Direct USB to NC2000
• Cloud via internet
• Bluetooth via 485-BT service tool to mobile

Alarms & monitoring

Email and push notifications. Data logging / trending over time. Helps diagnose issues remotely before dispatching a technician.

SEC firmware patch requirements

SkyQ will warn and not operate correctly without compatible firmware. Communication must be set to Modbus at 57,600 baud (done at factory when ordered with SkyQ option).

Selection Navigator quoting tool

Go to Selection Navigator → Light Commercial Controls. SkyQ options now replace Verasys options in the rooftop configurator.

How it works

• Name your system and add applications: single zone, multi-zone changeover bypass, multi-zone VAV, or I/O
• Associate previously configured rooftops, create new ones, or flag as third-party
• Tool validates selections: red X → green checkmark
• Generates bill of materials and submittal documents
• Order controls with rooftops or separately

What's included when a SkyQ option is selected on a rooftop

• Com card (Modbus communication)
• Communication protocol set to Modbus at the factory
• Baud rate set to 57,600

Pricing model & warranty

• Pay for hardware only — software downloads and cloud are free
• No licensing or subscription fees
• SkyQ warranty: 3 years (separate from RTU warranty; not covered by comfort plan)

Verasys vs SkyQ — device comparison

Verasys parts & post-sale support

• Replacement parts available through Source One — stocked ~7 years
• Prices have increased significantly — now priced as replacement parts
• Pre-sales support for new Verasys applications: no longer available
• Post-sale tech support: same team, same contact info

Migrating from Verasys to SkyQ

What you can reuse

• Existing field wiring
• NSA1000 sensors (single zone only — leave on wall)

What must change

• All controllers replaced (no hybrid systems)
• Multi-zone: new wall sensors required
• Zone wiring: disconnect wire from rooftop to first zone, reconnect to Zone Q
• Firmware patch on SEC controllers (v4 → 4.5; v5 → 5.2)

Same migration path applies to earlier YCCS systems at end of useful life.

Verasys vs SkyQ

Frequently asked questions

Support contacts

Key resources