1. Introduction
This manual provides instructions for the installation, operation, and maintenance of the ComWinTop RS485 Modbus Temperature Humidity Sensor Transmitter Transducer. This device is designed for detecting air temperature and humidity in various environments.
It is widely used in communication rooms, intelligent buildings, workshops, warehouses, medicine storage facilities, libraries, museums, laboratories, offices, and ventilation ducts. The unit features a wall-mounted ceiling structure and pin-type terminals for easy wiring.
Product Overview Video
2. Optional Types
The CWT-LCDTH series offers various models with internal or external sensors and different output types:
| Model | Picture | Descriptions |
|---|---|---|
| CWT-LCDTH-IS |
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| CWT-LCDTH-IA |
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| CWT-LCDTH-IV |
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| CWT-LCDTH-ES |
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| CWT-LCDTH-EA |
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| CWT-LCDTH-EV |
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3. Specifications
| Feature | Description |
|---|---|
| Voltage | DC9V-DC24V |
| Consumption | <0.1W |
| Measuring Range (Temperature) | -30 °C to 70 °C |
| Measuring Range (Humidity) | 0 ~ 100% rh |
| Measurement Accuracy (Temperature) | ± 0.3 °C at 25 °C |
| Measurement Accuracy (Humidity) | ± 3% rh at 25 °C |
| Screen | LCD display |
| Connection | Terminals |
| Protection | IP30 |
| Dimension | 86 × 86 × 35mm |
| Effective Working Area | 10-20m² (only) |
| Installation Method | Wall-mounted |
| Material | Fireproof ABS resin |
4. Setup
4.1. Physical Installation
The sensor is designed for wall-mounted installation. It features a built-in magnet at the bottom, allowing for screw-free installation on metal surfaces. For non-metal surfaces, standard wall mounting procedures should be followed.
4.2. Wiring
The device uses pin-type terminals for electrical connections. Ensure all power is disconnected before wiring to prevent electrical shock or damage to the device.
RS485 Connecting Parameters
| Parameter | Value/Description |
|---|---|
| Address | 1-254 (Set up by pressing buttons) |
| Protocol | MODBUS RTU |
| Baud Rate | 300-115200bps |
| Terminals |
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4-20mA or 0-5V/10V Connecting Parameters
| Terminal | Function |
|---|---|
| 1 | None |
| 2 (Hout) | Humidity output |
| 3 (Tout) | Temperature output |
| 4 (VCC) | Power + |
5. Operating Instructions
5.1. LCD Display
The integrated LCD display shows real-time temperature in degrees Celsius (°C) and relative humidity in percentage (%).
5.2. Button Functions
The device features four buttons: MENU, Up Arrow, Down Arrow, and ENTER. These buttons are used to navigate through settings and configure parameters such as the RS485 address.
- MENU: Accesses the device's configuration menu.
- Up Arrow: Increases values or navigates upwards in menu options.
- Down Arrow: Decreases values or navigates downwards in menu options.
- ENTER: Confirms selections or enters sub-menus.
To set the RS485 address (1-254), press the appropriate button (likely MENU) to enter the settings mode, then use the Up/Down arrows to adjust the address, and ENTER to save.
6. Maintenance
- Environmental Conditions: This device is not waterproof. Ensure it is installed in a dry environment to prevent damage.
- Cleaning: Clean the exterior of the device with a soft, dry cloth. Do not use abrasive cleaners or solvents.
- Material: The casing is made of fireproof ABS resin, providing durability and safety.
- Inspection: Periodically check wiring connections to ensure they are secure.
7. Troubleshooting
- No Display/Power: Ensure the power supply (DC9V-DC24V) is correctly connected to the VCC and GND terminals and is within the specified voltage range.
- Incorrect Readings: Verify that the sensor is installed in an area representative of the environment you wish to measure. Ensure no obstructions are blocking the sensor.
- Communication Issues (RS485): Check the RS485 A+ and B- connections. Confirm the device address and baud rate settings match your Modbus master device.
- No Analog Output (4-20mA/0-5V): Check the connections to Hout (humidity output) and Tout (temperature output) terminals. Ensure the receiving device is correctly configured for the expected analog signal type.
8. User Tips
- For optimal accuracy, avoid installing the sensor near heat sources, direct sunlight, or areas with poor air circulation.
- When configuring the RS485 address, keep a record of assigned addresses to prevent conflicts in a multi-device network.
- Consider the effective working area of 10-20m² when planning sensor placement for accurate environmental monitoring.
9. Warranty and Support
For detailed warranty information or technical support, please contact the seller, ComWinTop Store, directly through the platform where the product was purchased. Please refer to the user manual (PDF) for comprehensive details.
A PDF version of the user manual is available for download: User manual (PDF)