Digital Temperature Humidity Sensor Probe Instruction Manual

1. Introduction

This manual provides detailed instructions for the Gauselink Digital Temperature Humidity Sensor Probe, covering its specifications, setup, operation, maintenance, and troubleshooting. These sensors are designed for industrial use, offering precise and stable measurement of temperature and humidity with RS485 Modbus RTU communication.

2. Specifications

2.1 Product Parameters

2.2 Model Comparison

The model number format is GL-TH-XX-YYY, where:

• GL: Gauselink
• TH: Thermometer and Hygrometer
• XX: Identification Number
• YYY: Primary material of housing (PVC, PE, MT for metal)

Key differences between models:

• GL-TH01-PVC: Features a PVC shell. It is not waterproof but offers better ventilation, allowing for quicker response to temperature changes due to direct sensor contact with external air.
• GL-TH02-PE and GL-TH03-MT: These models are dustproof but not waterproof, with an IP44 protection level. Their porous caps filter dust, maintain good ventilation, and reduce vapor water condensation.
• GL-TH04-MT: This model is both waterproof and dustproof, offering an IP67 protection level.

All models share the same PCB design and sensor type, featuring an advanced temperature and humidity sensor from Switzerland for precise and stable data measurement.

3. Setup and Installation

3.1 Wiring Diagram

The sensor uses a 4-wire connection for power and RS485 communication. Ensure correct polarity and terminal connections.

• Brown: VCC (5 ~ 28V DC)
• Black: GND
• Yellow: RS485 A
• Blue: RS485 B

Note: Pay attention to the color-coded wires for correct connection. Before wiring, ensure the power is turned off.

3.2 Connecting to a PC

To connect the sensor to a PC, an RS485 to USB converter is required. If you purchased a SKU with a converter, it will be included. For Windows PCs, the CH340 driver needs to be installed, which can be downloaded from the internet. Contact Gauselink support if you need assistance with the driver.

3.3 Installation Methods

The sensor can be installed using two primary methods:

1. Panel/Wall Opening: The sensor can be installed directly into a panel or wall opening. Refer to the dimensions below for appropriate hole sizes.

2. Supporting Bracket: Brackets are available for mounting the sensors.

• A white plastic bracket is available specifically for the GL-TH01-PVC model.
• Metal brackets are available for GL-TH02, GL-TH03, and GL-TH04 models.

4. Operating Instructions

4.1 Modbus RTU Protocol

The sensor communicates using the Modbus RTU protocol. It can be connected to a PC, Microcontroller Unit (MCU), or Programmable Logic Controller (PLC) for data communication.

Basic Communication Parameters:

• Baud Rate: 9600 bps
• Data bit: 8
• Stop bit: 1
• Parity check: None
• Verification: CRC-16/ModBus
• Read Code: 0x03 (hexadecimal)
• Write Code: 0x06 (hexadecimal)

RS485 Modbus Protocol Format:

RS485 Modbus Register Definition:

4.2 Communication Examples

To read temperature:

• Host (TX): 01 03 00 01 00 01
• Client (RX): 01 03 02 XX XX

To read humidity:

• Host (TX): 01 03 00 00 00 01
• Client (RX): 01 03 02 XX XX

To read both humidity and temperature:

• Host (TX): 01 03 00 00 00 02
• Client (RX): 01 03 04 XX XX XX XX

How is temperature below 0°C presented?
If the temperature is a negative value, it will be expressed in Two's Complement Notation. For example, if the sensor yields hexadecimal data FF10, its binary notation is 1111 1111 0001 0000. In Two's Complement, this represents a negative value. To convert, flip the bits and add 1, resulting in 0000 0000 1111 0000, which is 240 in decimal. The real temperature value is -240/10 = -24°C.

For more information on Two's Complement, refer to Wikipedia.org.

To read Baud Rate:

• Host (TX): 01 03 07 D1 00 01
• Client (RX): 01 03 02 00 01

To read client address:

• Host (TX): 01 03 07 D0 00 01
• Client (RX): 01 03 02 00 01

To change client/sensor address from 01 to 02:

• Host (TX): 01 06 07 D0 00 02
• Client (RX): 01 06 07 D0 00 02

If the client address is forgotten, it can be checked by using a broadcast address 0xFF as a substitute, ensuring only one client is connected. For example:

• Host (TX): FF 03 07 D0 00 01
• Client (RX): 02 03 02 00 02 (The address is 0x02)

4.3 Temperature and Humidity Calibration Adjustment

Registers 0x0050 (Temperature) and 0x0051 (Humidity) are available for customer-specific adjustments if the temperature/humidity values need to be offset. The default value for these registers is 0.

Example:

• To offset the temperature by +2°C, set the value of register 0x0050 to 0x14.
  • Host (TX): 01 06 0050 0014
  • Client (RX): 01 06 0050 0014
• To increase the humidity by +5%, set the value of register 0x0051 to 0x32.
  • Host (TX): 01 06 0051 0032
  • Client (RX): 01 06 0051 0032

Note: Negative offset values must be expressed in Two's Complement Notation. For example, -2°C would be expressed as 0xFFEC.

4.4 Demonstration Video

5. Maintenance

• Keep the sensors clean. Avoid exposure to corrosive liquids or dust that may damage the probe.
• Avoid condensation. Do not immerse the sensor in liquid.
• The sensor is designed to detect air, not liquid. Do not immerse it in water.
• The sensor must be operated by qualified personnel.
• Always turn off the power before performing any wiring or maintenance.

6. Troubleshooting

6.1 No Output or Output Error

If you experience no output or an output error, consider the following:

• Baud Rate Setting: Ensure the Baud Rate is correctly set. The default Baud Rate is 9600bps.
• Wiring: Check if terminals A and B are mixed up in the wiring.
• Driver Installation: Verify that the driver for the USB to RS485 converter is properly installed on your PC.

7. User Tips

• Always double-check the color-coded wires against the wiring diagram to ensure correct connections, especially for VCC, GND, RS485 A, and RS485 B.
• For optimal performance and longevity, avoid placing the sensor in environments with direct exposure to corrosive substances or excessive dust, unless using an appropriately rated model (e.g., IP67 for GL-TH04-MT).

8. Applicable Fields

The Gauselink Digital Temperature Humidity Sensor Probes are suitable for a wide range of applications, including:

• Office environments
• Greenhouses and agricultural settings
• Laboratories and hospitals
• Warehouses storing sensitive materials or equipment
• Retail stores and pharmacies
• Environmental monitoring systems

9. Technical Support

Gauselink offers one-to-one technical support. If you require assistance with setup, operation, or troubleshooting, please contact our sales assistant online for prompt support.