Overview
This solution outlines the integration of the Smart Temp SMT-770 wall controller with the Danfoss PAC unit using a Rubix Compute 5 as the intermediary controller. The configuration enables automatic operation of rooftop packaged units (RTPUs) through the anywAiR iO platform.
FGA anywAiR iO RTPU Auto Mode
System Components
Rubix Compute 5 with 4G router and Modbus RS485 communication
Smart Temp SMT-770 wall controller
Danfoss Controller (PAC Unit)
Modbus 485 Serial Network for communication between devices
All programming and configuration are managed through Rubix CE Software.
FGA anywAiR iO RTPU Auto Mode
Functional Description
Auto Mode Operation
The SMT-770 controls the PAC unit through Modbus logic processed by Rubix Compute.
In Auto Mode, the system monitors the return air temperature (from the Danfoss controller) and adjusts compressor operation automatically:
Cooling Mode: Activates when room temperature rises above Setpoint + Deadband.
Heating Mode: Activates when temperature drops below Setpoint – Deadband.
The system returns to Ventilation Mode when within the deadband range.
FGA anywAiR iO RTPU Auto Mode
After Hours Mode
Activated via the Override button on the SMT-770.
Displays “Override” on the wall controller LCD while active.
Default duration: 120 minutes (adjustable).
FGA anywAiR iO RTPU Auto Mode
Programmable Modes
Residential Mode: Basic scheduling and setpoint control.
Commercial Mode: Full scheduling, after-hours operation, and setpoint lockout (default).
FGA anywAiR iO RTPU Auto Mode
Technical Parameters
Modbus Baud Rate: 9600
Danfoss Address: 10
SMT-770 Address: 7
Parity: None
Communication Type: RS485-1
Refer to the Danfoss Controller Setup and SMT-770 Points List in the attached technical guide for register mapping and control points.
FGA anywAiR iO RTPU Auto Mode
Key Functions
| Feature | Controller | Description |
|---|---|---|
| Setpoint Adjustment | SMT-770 | User-adjustable with upper and lower limits (18°C–30°C). |
| Auto Changeover | Rubix Compute | Automatically toggles between heating/cooling modes. |
| After Hours Override | SMT-770 | Temporary manual enable (120 mins default). |
| Error Display | SMT-770 | Displays “Error” if Danfoss fault detected via Modbus. |
Testing & Verification
Functional tests are outlined in Section 9.0 of the manual, including verification of:
Mode change response
Setpoint limits
Scheduling behaviour
After-hours override
Fault indication and recovery
FGA anywAiR iO RTPU Auto Mode
Summary
The FGA anywAiR iO RTPU Auto Mode system delivers integrated temperature control for rooftop packaged units using Smart Temp SMT-770 controllers and Danfoss drivers via Rubix Compute.
This setup provides:
Seamless auto changeover between heating and cooling,
User-friendly scheduling,
Remote management capability, and
Reliable fault monitoring.