Overview
This article provides information about which Fujitsu General air conditioning units include a UART (Universal Asynchronous Receiver/Transmitter) communication port, what it is used for, and how availability varies across models and production years.
1. What Is a UART Port?
The UART port is a communication interface located on the indoor unit control board.
It allows for:
Connection of optional communication devices, such as Wi-Fi modules or zone controllers.
Integration with third-party control systems, such as building management systems (BMS) or home automation platforms.
Diagnostic access for service tools in compatible models.
UART ports provide the physical connection point used by accessories like:
anywAiR® Wi-Fi Adaptors
UTY-TFSX or UTY-TFNXZ2 Interface Modules
Intesis and third-party communication gateways
2. Units Equipped with UART Ports
All Fujitsu General indoor units manufactured from 2022 onwards are equipped with at least one UART port on the indoor PCB as standard.
| Production Year | Series / Models | UART Port Availability | Notes |
|---|---|---|---|
| 2022 → Current | Wall Mounted Splits (e.g., ASTG, ASTH, ABTG series) | 1 UART port | Standard on all models |
| 2022 → Current | Cassette & Ducted Systems (ARTC, ARXC, AUTG, ARY series) | 1–2 UART ports | Dual UART on selected models for expanded connectivity |
| 2022 → Current | VRF Indoor Units (VR-II, J-IIIL, J-IIS, V-II, V-III series) | 1 UART port minimum | Some commercial models feature 2 UART ports for service and control access |
| Pre-2022 | Select models only | Not standard | Check model-specific wiring diagrams |
3. Dual UART Ports
Certain commercial indoor models and ducted units include two UART ports.
This allows simultaneous connection of:
A Wi-Fi adaptor (such as UTY-TFSXZ2)
A Wired controller or third-party gateway
Note: When connecting multiple devices, ensure correct wiring order and avoid exceeding communication load limits. Always refer to the unit’s installation manual for specific connection diagrams.
4. Identifying the UART Port
The UART connection is typically located on the indoor control PCB and labeled as:
CN105, CN107, CN106, or CN152, depending on the model.
It usually consists of a 3-pin or 4-pin connector with the following terminal configuration:
12 V DC power
Ground (GND)
Data (TX/RX)
Refer to the indoor unit wiring diagram or the installation manual for the exact connector position and pinout.
5. Common Uses
| Accessory / Function | Connected to UART Port? | Description |
|---|---|---|
| anywAiR® Wi-Fi Adaptor | ✅ Yes | Provides app-based control via the myanywAiR platform |
| Wired Remote Controller | ✅ Yes | Allows local control and scheduling |
| Third-Party Interface (Intesis / Modbus) | ✅ Yes | Enables BMS or home automation integration |
| Service Tool / VRF Diagnostic Device | ✅ Yes | Used by technicians for configuration and monitoring |
6. Service and Installation Notes
All units produced after 2022 will include at least one UART port; many commercial models include two.
Always confirm the UART port location and labeling before connecting any device.
Ensure power to the indoor unit is isolated before installation of communication accessories.
Do not connect multiple communication devices to the same port unless specifically approved.
7. Summary
| Unit Type | Year of Manufacture | UART Ports | Remarks |
|---|---|---|---|
| Residential Wall Split | 2022 and later | 1 | Standard UART on indoor PCB |
| Ducted / Cassette | 2022 and later | 1–2 | Dual port models allow Wi-Fi + controller connection |
| VRF Indoor Units | 2022 and later | 1 | Standard on all VRF indoor PCBs |
| Older Models (pre-2022) | — | Varies | May not include UART functionality |