Hotel-Room Object
Comprehensive, step-by-step manual for the Hotel-Room Object that you can use directly on the Hotel projects
Hospitality installations — guest rooms, PMS integration, and iNELS Harmony.
1. What it is
The Hotel-Room Object is a virtual device inside the CU3 central unit, designed specifically for hotel and hospitality projects. It aggregates all guest, room and climate functions into a single object, so the information is available to reception software, a PMS (Property Management System) or a BMS without handling dozens of separate signals.
Everything about a guest room — occupied or empty, do-not-disturb, temperature, window open — is unified in one place.
Why it matters
Instead of configuring dozens of signals separately, all values are consolidated in one object
PMS/BMS integration needs only one MQTT topic per room, which minimises complexity and errors
Housekeeping sees MUR and DND instantly in the PMS — no wasted trips to rooms
Maintenance can monitor HVAC performance (temperature, humidity, valve status) remotely
Reception gets real-time visibility of guest presence, alarms and scenes
Fewer manual processes → lower staffing costs and higher efficiency
Works equally for small boutique hotels and large multi-building resorts
Each CU3 handles more than one Hotel-Room object, all with the same interface
Use the iNELS Hotel Reservation Software (iHRS) or connect a third-party PMS/BMS
The open MQTT/JSON interface suits cloud platforms, custom dashboards and mobile apps

Rooms will not appear in iNELS Harmony without this object
This is the one that catches people out. You can wire a guest room perfectly — lights, heating, card reader, everything working — and the room still will not be discovered by iNELS Harmony.
Harmony finds rooms by looking for Hotel-Room objects. No object, no room. The installation works locally and looks finished, but the hotel's management layer sees nothing.
On any project that will use Harmony, add the Hotel-Room object from the start. Retrofitting it across eighty rooms after commissioning is a long, avoidable job.
2. Main features
Guest & room status
Occupancy, Do Not Disturb (DND), Make Up Room (MUR), Butler/service call
Climate control
Actual temperature, humidity, dew point, setpoints, correction
HVAC control
Mode, plan, fan speed
Room events
Door/window status, card events
Scenes
Welcome scene + 5 customisable room scenes
MQTT integration
One topic per room, JSON payload
Bidirectional
Both read status and write control are supported
3. Adding it to a project
You need a current iDM version for the Hotel object to be available, and current CU3 firmware (Chapter 25).
The structure is two levels:
One Hotel-Room unit per physical guest room. A forty-room floor is forty units under one module.
Step 1 — Add the module
Project ribbon tab → Device manager.
Select the central unit → New slave.
Choose
Hotel-Room-Modul→ OK.
The module has no parameters. It is a container.
Step 2 — Add a room
Select the
Hotel-Room-Modul.New unit →
Hotel-Room→ OK.Set its Description to something a human recognises —
Room 101.
Step 3 — Set the parameters
Select the Hotel-Room unit. In Parameters you will see:
Address
assigned by iDM3
Unique identifier of the object in the CU3
Name / Description
text
For project documentation
Room-Id
0 – 65535 (default 1)
Links the object to the hotel room number
Enter the hotel's actual room number as Room-Id. Room 101 gets 101; room 1204 gets 1204.
Room-Id is not the Address. They are different fields with different jobs, and the PMS integrator needs both:
Address
iDM3
the central unit, and the MQTT topic
Room-Id
you
the PMS, Harmony, and the hotel
Get Room-Id right the first time. It is how the PMS and Harmony identify the room. Changing it later means the management system loses track of that room until its own configuration is updated to match.
Rooms with no number. Give staff rooms, plant rooms and suites a consistent scheme —
9001upwards, say — rather than leaving them at the default1. Two objects sharing Room-Id1is a problem you will find late.
Repeat steps 2 and 3 for every room.
4. Device structure — the 23 datapoints
Expand a Hotel-Room unit and you will find 23 devices. They are ordinary iNELS objects: wire them, use them in conditions, read them in Monitor. The names in brackets are what you will see in the device tree.
Guest & room status
Occupancy
Guest in room (true/false)
DND
Do Not Disturb
MUR
Make Up Room
Buttler
Service call
"Buttler" is spelled that way in the software — with two t's. You are looking at the right datapoint.
Climate control
Actual-Therm-AOUT
Actual temperature
Required-Heat-Therm-AOUT
Required heat setpoint
Required-Cool-Therm-AOUT
Required cool setpoint
Set-Therm-AIN
The temperature the guest or PMS is asking for
Correction
Calibration offset
Humidity-AOUT
Relative humidity
Dew-Point-AOUT
Dew point
Read the suffixes.
-AOUTdatapoints are values the object publishes — what the room is doing.-AINdatapoints are written into the object — what someone is asking for.
Dew point matters more than it sounds. In humid climates, cooling below the dew point causes condensation on chilled surfaces. Hotels commonly use this datapoint to limit how far cooling can go.
HVAC control
Control-IN
Heat / Cool / Off
Control-Mode-IN
Plan / Manual / Eco / Dry etc.
Control-Plan-IN
Base / Holiday / Public Holiday
Control-Fan-Speed-IN
Low / Medium / High / Auto / Off
The numeric values behind each of these are in the Payload reference at the end of this page.
Room events
Door-Status
Open / Closed
Window-Status
Open / Closed
Scenes
Welcome-Scene
Triggered when a guest first enters
Scene1 – Scene5
Five further scenes, customisable
5. Linking to a Heat/Cool controller
The Hotel-Room object holds the guest's request. A Heat/Cool area (HCA) is what regulates the room (Chapter 10). They have to be joined.
Add a Controller for Heating and Cooling (HCA) in System manager → Heat/Cool areas tab.
Under Connections, select the Hotel-Room object for this room.

iDM will automatically create internal wires between the Hotel-Room object and the HCA. The climate data — actual temperature, required heat setpoint, required cool setpoint, correction, humidity, dew point — is wired for you.
Important: You must still wire the HCA outputs (Fan regulator, Valve regulator) to the physical output relays or analog outputs controlling the HVAC equipment.
The automatic linking connects the object to the controller, not the controller to the hardware. A room where the guest can set a temperature, the PMS shows it correctly, and nothing physically happens is almost always this step, left undone.
Repeat per room — eighty rooms means eighty Heat/Cool areas.
6. Wiring it to the room hardware
The automatic link covers climate. Everything else you wire yourself, using the ordinary actor → function → consumer model (Chapter 2).
Occupancy from a card holder
Card holder input
Digital IN switch ON
DIGITAL_ON
Occupancy
Card holder input
Digital IN switch OFF
DIGITAL_OFF
Occupancy
Then use Occupancy as an actor for everything that should follow the guest:
Occupancy
Digital IN switch ON
DIGITAL_ON
Welcome-Scene
Occupancy
Digital IN switch OFF
DIGITAL_GROUP_OFF
room lights group
Occupancy
Digital IN switch OFF
HEATING_COOLING_SWITCH_TO_FAVORITE1
the room's HCA
That last wire is where a hotel saves most of its energy: an empty room falls back to setback temperature automatically.
DND, MUR and butler from the guest panel
Use a GSB3 glass switch — a GSB3-60 or GSB3-90, for example — as the bedside or entrance panel, with one button per guest function.
GSB3 button 1
Short down
DIGITAL_SWITCH
DND
GSB3 button 2
Short down
DIGITAL_SWITCH
MUR
GSB3 button 3
Short down
DIGITAL_ON
Buttler
DND
Digital IN switch ON
DIGITAL_ON
GSB3 button 1 backlight
Drive the backlights from the datapoint, not the button. Guests need to see whether DND is on. Taking the indication from the DND datapoint means the lamp always shows the real state — including when housekeeping or the PMS clears it remotely, which a button-driven indicator would miss entirely.
The older EST3 and EHT3 hotel panels are obsolete. They still appear in the unit list so you can service existing installations, but do not specify them for new work. Use a GSB3 or current equivalent.
Door and window
Door contact
Digital IN switch ON
DIGITAL_ON
Door-Status
Window contact
Digital IN switch ON
DIGITAL_ON
Window-Status
Window-Status is worth wiring even where the hotel has not asked for it: the HCA can suspend heating while a window is open, which pays for the contact quickly.
Scenes
Wire Welcome-Scene and Scene1–Scene5 to lighting groups, blinds or the television. Because they are datapoints on the object, the PMS can trigger them too — so a scene can be fired by the front desk as easily as by the guest.
Useful patterns
Setback when the guest leaves
Occupancy off → HEATING_COOLING_SWITCH_TO_FAVORITE1
No housekeeping while DND is on
Condition: Restriction value — DND = OFF
Stop cooling below dew point
Condition comparing Dew-Point-AOUT against the cooling setpoint
Heating off with a window open
Window-Status as a condition, or the HCA's window handling
Lights off when the room empties
Occupancy off → DIGITAL_GROUP_OFF on the room lighting group
Welcome on first entry
Occupancy on → DIGITAL_ON on Welcome-Scene
7. MQTT integration
Topic Structure
Status (publish)
Set (subscribe)
Example Status Payload
Example Set Payload
Payload reference
Fan Speed
0
Low
Fan at low speed
1
Med
Fan at medium speed
2
Hi
Fan at high speed
3
Auto
Automatic fan speed control
4
Off
Fan switched off
HVAC control
0
Cool
Cooling mode active
1
Heat
Heating mode active
2
Off
System switched off
HVAC Modes
0
Cool
Cooling mode active
1
Heat
Heating mode active
2
Off
System switched off
Control Modes
0
Plan
Follow scheduled plan
1
Favorite1
User-defined favorite mode 1
2
Favorite2
User-defined favorite mode 2
3
Favorite3
User-defined favorite mode 3
4
Favorite4
User-defined favorite mode 4
5
Fan
Fan-only mode
6
Eco
Energy-saving mode
7
Manual
Manual override mode
8
Dry
Dehumidification mode
Plan Control Modes
0
Base
Base (default) plan
64
Holiday
Holiday plan
128
Public Holiday
Public holiday plan (special case)
8. If a room does not appear in iNELS Harmony
Does the room have a Hotel-Room unit?
No object, no room — see §1
Is the Room-Id set and unique?
Two rooms sharing an Id will not both appear
Was the project uploaded?
Save to central unit
Is MQTT enabled and connected?
Is the CU3 firmware current?
9. Before handover
See also: Chapter 10 — Heating and cooling · Chapter 20 — System manager · Chapter 24 — External systems
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