Short Answer
Yes. The iSMA RAC18-IP is N4 programmable and can be engineered directly from Niagara Workbench using the nE2 Link extension. However, it does not run a full Niagara station in the same way as a JACE, Distech ECL, Honeywell CIPer, or iSMA MAC36NL controller. Instead, it runs iSMA's nano Edge Engine, providing real-time graphical programming and control at the edge.
Is the RAC18-IP N4 Programmable?
Yes.
The RAC18-IP was designed as a Niagara-enabled, freely programmable IP controller. Control logic can be created and modified directly from Niagara Workbench using the nE2 Link extension, allowing real-time wiresheet programming on the controller.
Key Points
-
Freely programmable controller.
-
Supports real-time programming from Niagara Workbench.
-
Suitable for custom HVAC, room and zone control applications.
-
Not limited to fixed-function FCU applications.
2. Does the RAC18-IP Run a Niagara Station?
No.
This is the most important distinction to understand.
The RAC18-IP is Niagara-enabled, but it does not host a full Niagara station. Instead, it runs iSMA's nano Edge Engine and executes control logic locally on the controller.
What This Means
Advantages
-
Lower hardware overhead.
-
Fast deployment.
-
Real-time control execution.
-
Lower cost than a full Niagara controller.
Limitations
-
Does not provide local Niagara station functionality.
-
Not intended to replace a JACE or Supervisor.
-
Less suited to applications requiring extensive supervisory functions.
3. What Software Is Required?
The RAC18-IP can be programmed using either of the following tools:
Option 1 – Niagara Workbench
-
Niagara Workbench
-
iSMA nE2 Link extension
This allows programming and management directly from the Niagara environment.
Option 2 – iC Tool
-
Free standalone iSMA engineering software
-
Supports programming and maintenance of connected devices
This is useful where Niagara Workbench is not available or required.
4. Can Additional I/O Be Added?
Yes.
The RAC18-IP includes:
-
18 onboard I/O points
-
2-port Ethernet switch
-
RS485 communications port
-
Support for expansion devices over Ethernet and RS485 networks.
Typical Expansion Options
-
iSMA MIX series I/O modules
-
Modbus RTU I/O modules
-
Modbus TCP devices
-
BACnet/IP devices
Rule of Thumb
If the application naturally fits within approximately 18–30 points, the RAC18-IP is usually a good fit.
If multiple expansion modules are required, a larger controller platform may be a more efficient engineering choice.
5. Typical Applications
The RAC18-IP is intended for room, zone and light plant control applications.
Suitable Applications
-
Fan Coil Units (FCUs)
-
Variable Air Volume (VAV) control
-
Room control
-
Zone control
-
Small Air Handling Units (AHUs)
-
Lighting control
-
Blind control
-
Small HVAC applications requiring onboard I/O and Ethernet connectivity.
Communications
The controller supports:
-
BACnet
-
Modbus
-
MQTT
allowing integration with a wide range of Building Management Systems and third-party devices.
Summary
The RAC18-IP is a Niagara-enabled, N4 programmable edge controller that can be engineered directly from Niagara Workbench using nE2 Link or through the standalone iC Tool. It does not run a full Niagara station, but provides a cost-effective and flexible platform for room, zone and light HVAC control applications with options for I/O expansion and integration via BACnet, Modbus and MQTT.
I need something larger but not a full station
If you're looking purely at RAC18-IP vs UAC28-IP, our view is that the UAC28-IP is essentially the "big brother" of the RAC18-IP, aimed at plant and packaged HVAC equipment rather than room control.
At a Glance
|
Feature |
RAC18-IP |
UAC28-IP |
|---|---|---|
|
Controller Type |
Room Application Controller |
Unitary Application Controller |
|
Nano Edge Engine |
Yes |
Yes |
|
Niagara Workbench Programming |
Yes (nE2 Link) |
Yes (nE2 Link) |
|
Full Niagara Station |
No |
No |
|
Onboard I/O |
18 |
28 |
|
Ethernet |
2-port fail-safe switch |
2-port fail-safe switch |
|
RS485 |
Yes |
Yes |
|
Built-in Web Server |
Basic support |
Yes, HTML5 visualisation |
|
Intended Applications |
FCU, VAV, room and zone control |
AHUs, cooling towers, heating/cooling substations, plant control |
|
ASHRAE 36 Function Blocks |
No |
Yes |
|
I/O Expansion |
Yes |
Yes |
Programming
From a programming perspective they are very similar.
Both controllers:
-
Use the nano Edge Engine.
-
Can be programmed from Niagara Workbench using nE2 Link.
-
Can be programmed using iC Tool.
-
Do not run a full Niagara station.
If you've learned one, you'll feel at home with the other.
Where the UAC28-IP Pulls Ahead
1. More I/O
The RAC18-IP provides 18 onboard I/O.
The UAC28-IP provides 28 onboard I/O.
For example:
RAC18-IP
-
FCU
-
VAV
-
Small extract system
-
Single zone application
UAC28-IP
-
Full AHU
-
Heat recovery unit
-
Cooling tower
-
LTHW substation
-
Packaged plant
2. Intended for Plant Control
The UAC28-IP is explicitly marketed for:
-
AHUs
-
Cooling towers
-
Heating substations
-
Cooling substations
-
Various HVAC plant applications.
The RAC18-IP is primarily targeted at:
-
Rooms
-
Zones
-
FCUs
-
Lighting
-
Blind control.
3. ASHRAE 36 HVAC Libraries
This is probably the biggest engineering difference.
The UAC28-IP includes HVAC applications built around ASHRAE Guideline 36 function blocks for AHU control.
For an engineer this means:
Supply fan
Return fan
Economiser
Supply air reset
Pressure control
Frost protection
Which can be assembled much faster using predefined HVAC blocks.
The RAC18-IP doesn't appear to be positioned around these larger HVAC application libraries.
4. Better Future Expansion
The UAC28-IP literature specifically references expansion using multiprotocol I/O modules ranging from 4 to 38 I/O and highlights scalability for future system growth.
That makes me much more comfortable specifying it for:
-
Hospital AHUs
-
Energy centres
-
Large packaged HVAC systems
Our Verdict
RAC18-IP = Modern room controller. RAC18-IP_Datasheet_DBL622en_V1.7.pdf
UAC28-IP = Modern plant controller. UAC28-IP_Datasheet_DBL733en_V1.0.pdf
The programming workflow is almost identical, so the choice is less about software and more about application size. For anything beyond room control, especially AHUs, I'd probably choose the UAC28-IP first because the extra I/O and ASHRAE 36 HVAC libraries make it a much more natural fit for plant applications.
If you need more help:
Then why not contact our sales or support team.
sales@forestrock.co.uk or support@forestrock.co.uk
Other Resources & Customer Survey:
💬 Don't miss out! Follow the Forest Rock News channel on WhatsApp Click Here!
💬 We’d also love your feedback! Please take a moment to complete our quick Customer Survey
It only takes a minute and helps us serve you better!
IoT Devices for BMS, Automation & Smart Connectivity | Forest Rock