Part of TCMsys
TCM Module
One module per room, sitting between the air-conditioning unit and the guest. It drives the unit directly, carries every guest-facing button in the room, reports live temperature back to the dashboard, and has the room ready before the guest reaches the door.
- Direct AC control, 8 brands
- Keycard · DND · Make my room · Laundry
- Live temperature & setpoint
- Pre-arrival comfort
The room device
Everything the room does, in one box
Most building systems treat the air conditioner and the guest-request panel as two unrelated things, wired separately, reporting to different places. In a hotel they are the same problem: whether the room is occupied determines what the unit should be doing, and what the guest wants determines whether anyone should walk to the door.
The TCM Module does both. It speaks to the air-conditioning unit over its own service interface — the same connection the manufacturer’s own controller uses — and it reads six opto-isolated inputs from the room. One device, one cable run, one thing to commission and one thing to replace.
It is powered from the room’s mains circuit through an isolated converter on the board, so there is no central low-voltage supply to design, run or fail. Each room is independent.
- Operating temperature
- 0 °C to +50 °C
- Storage temperature
- −20 °C to +70 °C
- Humidity
- 10–90 % RH, non-condensing
- Ingress protection
- IP20, indoor
- Supply
- 85–265 V AC, 50/60 Hz
- Power draw
- Under 3 W
- Protection
- Fuse, surge and TVS clamping
- Guest inputs
- Opto-isolated, 5 kV rms
Certification targets: CE, BIS, FCC and UL. Pre-compliance review is part of the hardware process rather than something discovered at the end of it.
Guest signals
The buttons in the room actually go somewhere
Do-not-disturb, make-my-room and laundry are not indicator lights on a wall plate. They are events, timestamped against a room, sitting in a queue that a supervisor is working from.
Keycard
OccupancyThe single most useful signal in the building. It tells the system the room is occupied, releases setback, and starts the clock on everything else — energy policy, housekeeping state, security logic.
Do Not Disturb
Guest requestThe moment the guest presses it, housekeeping sees it. No knocking on the door of a guest who asked not to be disturbed, and no cleaning round wasted walking to a room that will not open.
Make My Room
Guest requestRaises a cleaning request against that specific room with a timestamp, so the supervisor is scheduling against real demand rather than a fixed round.
Pick My Laundry
Guest requestA laundry pickup request routed straight into the housekeeping queue. The guest gets an acknowledgement that something happened; the floor supervisor gets a task.
Door
Safety & energyOpto-isolated 230 V detection. Feeds the door-open alarm, the security logic for an unoccupied room, and the AC policy for a door propped open on a hot afternoon.
Auxiliary
SpareA sixth opto-isolated channel with configurable polarity, assigned at commissioning. For the input that only this building has.
Assigned, not hardwired. All five input channels plus the auxiliary are configured at commissioning rather than fixed at the factory. A building that wires its panel differently does not need a different part number — and a stuck input is detected and flagged rather than quietly masking real state changes.
Realtime
What the room is doing, now
A control system whose screen disagrees with the room is worse than no screen at all. The module polls the unit continuously and pushes changes up rather than waiting to be asked.
Live room temperature
The module reads the actual measured temperature from the AC unit itself — not an inferred value, not a separate sensor with its own drift. It is on the dashboard within a second of changing.
Setpoint, both ways
You can see what the room is set to and change it from the dashboard. When a guest changes it on the remote, you see that too. There is no divergence between what the screen says and what the room is doing.
Full unit state
Mode, fan speed, vane positions, filter status and the manufacturer’s own error codes — translated into readable descriptions rather than shown as raw hex.
One-second event path
Any change of state on any input is detected and reported within a second of the physical event, with at-least-once delivery. An unacknowledged event is retried on the next cycle rather than dropped.
What the system sets
- Power on / off
- Mode — cool, heat, dry, fan, auto
- Setpoint temperature
- Fan speed
- Vertical vane position
- Horizontal / wide vane position
- External room temperature override
What the system reads back
- Power state and current mode
- Active setpoint
- Measured room temperature
- Fan speed and vane positions
- Filter status
- Manufacturer error and fault codes
Pre-arrival comfort
The room is ready before the guest is
This is the feature guests notice and never mention. Walking into a room that is already at temperature reads as a well-run hotel; walking into one that is not reads as a cheap one.
The booking is known
Your property management system tells us a guest is arriving and when. Reservations, amendments and cancellations all flow through the same path.
The room prepares itself
A configurable number of minutes before arrival, the module brings the unit to the comfort setpoint you have set for that room type. Not the whole floor — the room the guest is actually walking into.
The guest walks in
The room is already at temperature. Arrival comfort stops being a matter of how long ago housekeeping happened to leave the unit running.
The room releases
On checkout the room reverts to your vacant policy. Nothing is left cooling an empty room because someone forgot to turn it off.
And when nothing is listening
Everything above depends on the network. What follows does not. The module stores its own configuration and keeps enforcing it whether or not the gateway, the site server or the property management system is reachable — which is why the energy case survives an outage and the guest never finds out there was one.
The guest’s own remote keeps working throughout, within the limits you have set. Autonomy is not a degraded mode; it is the default the room falls back to.
Held on the module itself
- Setback policy and delay, per room or per floor
- Door-alarm behaviour and the AC action it triggers
- Failsafe mode when the gateway is unreachable
- Bus address and commissioned room identity
- Last AC state, re-applied within moments of power returning
Compatibility
Which units it drives
One module handles one unit over one interface. Which interface is set by the variant you order, so you pay for the connector the room actually needs — and modules on the same bus segment can be driving entirely different brands.
Mitsubishi Electric
- Notes
- Full feature set, over the unit’s own service port — no third-party gateway needed.
Daikin
- Notes
- S21 / D-BUS. Covers residential and light-commercial units.
LG
- Notes
- LGAP / PI-485 gateway protocol, including VRF systems.
Samsung
- Notes
- NASA protocol for DVM systems.
Panasonic
- Notes
- CS-CZ / CZ-CFUNC2. Adapter module required on some models.
Hitachi
- Notes
- H-LINK and H-LINK II for newer VRF models.
Toshiba
- Notes
- AB protocol.
Carrier / Trane
- Notes
- BACnet MS/TP. Available as a firmware extension on request.
Units outside this list can usually be added — send us the model and the protocol documentation.
Firmware over the bus
Updates stage to on-board memory while the room carries on being controlled, then apply at reboot behind a checksum. A failed transfer leaves the module on the firmware it had.
Replaceable in minutes
Scan the replacement, pick the room, and it inherits the address and mapping of the unit it replaced. Both serial numbers are recorded.
Recovers its own identity
A module that loses its address is rediscovered, matched to the commissioned room list by factory serial, and reassigned automatically.
TCMsys
The whole system the module belongs to — gateways, coordinator, dashboard, energy reporting and integration, up to 2,048 rooms per site.
Read moreKnode
The same module packaged as a standalone product for hotels running Mitsubishi units, where keycard-driven AC control is all you need.
Read moreTnode
The commercial equivalent — Mitsubishi AC control for offices and workspaces, driven from a phone rather than a front desk.
Read moreHow many rooms, and what is installed in them?
Send us a room count and the AC brands on site. We will tell you which module variant each room needs, what the cabling looks like, and what it costs to put the whole building on one system.