Wanas ST-340 V2
Controls and monitors WANAS recuperators via Modbus RTU
Template for WANAS ST-340 V2 recuperators via Modbus RTU. Reads airflow, temperatures, filter status, and zone data. Allows control of zone run modes, bypass, fireplace, and party functions.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 42, read and write
- Brand
- Wanas
- Key readings
- Supply and exhaust airflow · Outside, supply, exhaust, room temp · Supply and exhaust gear · Zone 1 to 5 temperatures · Filter change days · Bypass, heater, cooler status
- Available commands
- Zone 1 to 5 run mode · Bypass menu · Fireplace function · Party function
- Compatible models
- WANAS 815 V HI-TECH
- Last updated
Registers (42)
42 read, 9 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Supply airflow | m³/h | Read | |||
| Exhaust airflow | m³/h | Read | |||
| Supply gear | Read | ||||
| Exhaust gear | Read | ||||
| Outside temp. | °C | Read | |||
| Exhaust temp. | °C | Read | |||
| Supply temp. | °C | Read | |||
| Room temp. | °C | Read | |||
| Day of week | Read and write | ||||
| End of zone 1 ( start of zone 2) | min | Read | |||
| End of zone 2 ( start of zone 3) | min | Read | |||
| End of zone 3 ( start of zone 4) | min | Read | |||
| End of zone 4 ( start of zone 5) | min | Read | |||
| Zone 1 run | Read and write | ||||
| Zone 2 run | Read and write | ||||
| Zone 3 run | Read and write | ||||
| Zone 4 run | Read and write | ||||
| Zone 5 run | Read and write | ||||
| Zone 1 temp. | °C | Read | |||
| Zone 2 temp. | °C | Read | |||
| Zone 3 temp. | °C | Read | |||
| Zone 4 temp. | °C | Read | |||
| Zone 5 temp. | °C | Read | |||
| Communication parameters | Read | ||||
| Extra Temp | °C | Read | |||
| Ground heat exchanger | Read | ||||
| Bypass | — | Read | |||
| Humidifier | Read | ||||
| Heater | Read | ||||
| Cooler | Read | ||||
| Holiday | Read | ||||
| Filter change | — | Read | |||
| Ground heat exchanger menu | Read | ||||
| Bypass menu | Read and write | ||||
| Heater menu | Read | ||||
| Cooler menu | Read | ||||
| Fireplace function | Read and write | ||||
| Party function | Read and write | ||||
| Canopy input | Read | ||||
| Fire input | Read | ||||
| Data | Read | ||||
| Hour | Read |
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Use cases
- Monitor supply and exhaust airflow in real time to verify balanced ventilation performance.
- Track filter change countdown days and create alerts to schedule timely maintenance visits.
- Adjust zone run modes remotely for zones 1 through 5 without an on-site visit.
- Activate the fireplace function remotely when the end user reports negative pressure issues.
- Create an alert when outside or room temperature deviates beyond acceptable thresholds for more than 15 minutes.
- Use the party function to temporarily boost ventilation during high-occupancy events.
Installation
Connect the Modbus RTU wiring (A and B terminals) from the WANAS ST-340 V2 controller to the RS-485 port on your ModbusCloud Gateway.
Set the baud rate on the gateway to 19200 with odd parity (8O1) to match the WANAS controller defaults.
Verify the Modbus slave address on the ST-340 V2 controller and confirm communication parameters by reading register address 26.
Import the WANAS ST-340 V2 template from the ModbusCloud template library into your project.
Assign the correct slave address in the ModbusCloud configuration and verify that register values appear on the dashboard.
Test write functionality by toggling a zone run mode or activating the party function from the ModbusCloud interface.
Things to watch for
I cannot establish communication with the WANAS ST-340 V2. What should I check?
Confirm that the baud rate is set to 19200 and parity is set to odd (8O1) on both the gateway and the controller. Check RS-485 wiring polarity (A and B) and verify the correct slave address. You can read register 26 to confirm the device communication parameters.
What data type do the registers use?
All registers on the ST-340 V2 use uint16 (unsigned 16-bit integer). No special byte order or scaling conversions are needed beyond what the template provides.
Is the template compatible with other WANAS recuperator models besides the 815 V HI-TECH?
The template has been verified with the WANAS 815 V HI-TECH. Other WANAS models using the ST-340 V2 controller may work, but register compatibility should be confirmed before relying on the data.
Can I control all five zones independently?
Yes. The template provides separate write registers for zone 1 through zone 5 run modes, allowing independent scheduling and control of each zone from the ModbusCloud dashboard.
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