The IntesisBOX PA-RC2-MBS-1 (order code INMBSPAN001R000) is a Modbus gateway by Intesis (HMS Networks) that interfaces Panasonic ECOi and PACi air conditioning indoor units with Modbus RTU (EIA-485) networks. TapHome connects to the gateway via Modbus TCP using a TCP-to-RTU bridge — the gateway itself communicates with the AC unit over the proprietary Panasonic R1R2 bus.
The template provides ON/OFF control, operating mode selection, fan speed adjustment, vane position control, thermostat with setpoint and current temperature, and error code monitoring.
Wiring
The gateway has two connection ports:
- R1R2 connector (2 poles) — connects to the Panasonic AC indoor unit’s R1R2 bus (no polarity, max 500 m)
- EIA-485 connector (2 poles, A+ B-) — connects to the Modbus RTU bus (daisy-chain only, max 1,200 m)
The gateway is powered directly from the AC indoor unit — no external power supply is needed.
Do not install more than one wired remote controller on the same R1R2 bus. If both the Intesis gateway and a Panasonic wired remote controller are connected to the same bus, communication may shut down.
EIA-485 bus termination
A 120 ohm termination resistor is required at each end of the EIA-485 bus. The gateway has a built-in 120 ohm resistor that can be activated via DIP switch SW4-P4. Enable it only if the gateway is at the end of the bus.
DIP switch configuration
The gateway has three DIP switch banks: SW1 (AC features), SW3 (Modbus address and baud rate), and SW4 (temperature format, baud rate, termination). All changes require a power cycle.
Temperature scaling (SW4-P1) — important for TapHome
The TapHome template divides temperature register values by 100. The default DIP switch setting sends temperature in degrees (x1), which would result in incorrect readings.
Set SW4-P1 to ON (decicelsius / x10 mode) so that a setpoint of 22.0 C is transmitted as 220 in the register. The template then divides by 100, yielding 2.2 C — which is still incorrect at x10.
The template uses a division factor of 100, but the DIP switch x10 mode sends values multiplied by 10. With default DIP settings (x1), a value of 22 divided by 100 gives 0.22 C. With x10, a value of 220 divided by 100 gives 2.2 C. Neither matches the expected temperature. Verify the actual register values with the Modbus debug tool in TapHome and adjust the DIP switch or template scaling as needed for your installation.
Modbus address (SW3-P1..P6)
Binary-encoded slave address, range 1-63. Default: 1 (only P1 is ON).
Baud rate (SW3-P7..P8 + SW4-P3)
Default: 9600 bps. Available rates: 2400, 4800, 9600, 19200, 38400, 57600, 76800, 115200 bps.
Temperature and termination (SW4-P1..P2, SW4-P4)
| SW4-P1 | Description |
|---|---|
| OFF | Temperature in degrees, ×1 (Default) |
| ON | Temperature in decidegrees, ×10 |
| SW4-P2 | Description |
|---|---|
| OFF | Temperature in Celsius (Default) |
| ON | Temperature in Fahrenheit |
| SW4-P4 | Description |
|---|---|
| OFF | EIA-485 bus without termination resistor (Default) |
| ON | Internal 120 Ω termination resistor connected |
TapHome connection
Since the IntesisBOX communicates via Modbus RTU (EIA-485), a Modbus TCP-to-RTU bridge is required between TapHome Core and the EIA-485 bus. TapHome connects to the bridge over the local network using Modbus TCP.
When importing the template in TapHome, provide:
- IP Address — the TCP-to-RTU bridge’s IP on the local network (default: 192.168.0.1)
- Slave ID — the gateway’s Modbus address set via DIP switches (default: 1)
Assign a static IP address to the TCP-to-RTU bridge in the router’s DHCP settings to prevent the address from changing after a power cycle.
Device capabilities
The template exposes 6 devices communicating over holding registers H:0 through H:11.
ON/OFF
Simple switch to turn the AC unit on or off. Reads and writes register H:0 (Bool). Poll interval: 2.5 s.
Mode
Operating mode selector with 5 standard modes documented by Intesis:
| Value | Mode |
|---|---|
| 0 | Auto |
| 1 | Heat |
| 2 | Dry |
| 3 | Fan |
| 4 | Cool |
The template defines 10 positions (values 0-9). Values 5-9 are not documented in the user manual and may be available on specific Panasonic models — most installations will only use the first five.
Reads and writes register H:1 (Int16). Poll interval: 2.5 s.
Fan Speed
Fan speed selector with 4 standard speeds documented by Intesis:
| Value | Speed |
|---|---|
| 0 | Auto |
| 1 | Low |
| 2 | Mid |
| 3 | High |
The template defines 10 positions (values 0-9). The number of available fan speeds depends on the connected AC model — register H:21 reports the maximum number of fan speeds supported. Values beyond the model’s maximum will have no effect.
Reads and writes register H:2 (Int16). Poll interval: 2.5 s.
Vane Position
Vertical vane (louver) position control:
| Value (template) | Position |
|---|---|
| 0 | Auto |
| 1 | Position 1 (Horizontal) |
| 2 | Position 2 (Horizontal) |
| 3 | Position 3 (Mid) |
| 4 | Position 4 (Vertical) |
| 5 | Swing |
| 6 | Position 5 (Vertical) |
| 9 | Swirl |
The user manual documents Swing as value 10, but the template maps it to value 5 to create a contiguous range for the multi-value switch. Values 7 and 8 are positional placeholders. Swirl (value 9) is a rotational airflow pattern available on select Panasonic models.
Reads and writes register H:3 (Int16). Poll interval: 2.5 s.
Thermostat
Temperature setpoint (register H:4, read/write) and current reference temperature (register H:5, read-only). The template divides read values by 100 and multiplies written values by 100.
Temperature range: 16-32 C (default setpoint range, model-dependent). The reference temperature shows the AC unit’s own sensor reading unless an external sensor value has been written to register H:22.
Poll interval: 2.5 s.
Error Code
Read-only numeric value from register H:11. Key values:
| Value | Meaning |
|---|---|
| 0 | No error |
| 65535 (-1) | Communication error between gateway and AC unit |
| Other | Panasonic error code (see user manual Section 7 for 80+ error codes) |
Common error categories: A01-A30 (GHP engine), C01-C31 (central controller), E01-E31 (addressing/communication), F01-F31 (sensor faults), H01-H31 (compressor), L01-L25 (settings), P01-P31 (indoor/outdoor unit).
Poll interval: 15 s.
Additional capabilities not in template
The gateway exposes several registers that are not included in the current TapHome template but could be added manually:
| Register | Name | Type | Description |
|---|---|---|---|
| H:6 | Window Contact | R/W | Energy saving — turns off AC when window opens |
| H:9 | Operation Time | R/W | Running hours counter (non-volatile) |
| H:10 | Alarm Status | R | Binary alarm indicator (0/1) |
| H:22 | External Sensor Temperature | R/W | Overrides indoor unit’s built-in sensor |
| H:44 | Filter Status | R | Filter replacement indicator |
Troubleshooting
No Modbus communication
- Verify the R1R2 bus is connected between the gateway and the AC indoor unit — the gateway requires AC unit power
- Check the green LED (L1): normal operation shows 100 ms ON / 1,900 ms OFF pattern; 500 ms ON / 500 ms OFF indicates a communication error
- Confirm the slave address in TapHome matches the DIP switch setting on the gateway
- Ensure the TCP-to-RTU bridge is on the same network as TapHome Core
Error code 65535 continuously
This indicates the gateway cannot communicate with the AC indoor unit over the R1R2 bus. Check the R1R2 wiring and verify the AC unit is powered on.
Temperature values are incorrect
The template uses a division factor of 100 for temperature registers. Verify the DIP switch SW4-P1 and SW4-P2 settings match the expected scaling. See the DIP switch configuration section above for details.
