New Arrivals:EBYTE KTH2-R Series Probe-Type RS485 Temperature and Humidity Transmitters

In industrial automation, environmental monitoring, and smart buildings, accurate collection and reliable transmission of temperature and humidity data are critical to ensuring stable system operation. The KTH2-R series probe-type RS485 temperature and humidity transmitters launched by Chengdu EBYTE Electronic Technology Co., Ltd. have become a reliable choice for numerous application scenarios due to their high precision, industrial-grade design, and flexible installation methods. This article will provide an in-depth analysis of this product series and offer clear selection and application guidelines.

Overview of KTH2-R Series Probe-Type RS485 Temperature and Humidity Transmitters

The KTH2-R series is a temperature and humidity transmitter designed specifically for scenarios requiring probe-type measurement. While its core functions are consistent, the series is differentiated by probe connector materials to adapt to different installation environments and medium requirements.

Unified Core Advantages of the Series

• High-Precision Integrated Sensor: Adopts a high-precision digital temperature and humidity sensor with a temperature accuracy of ±0.2°C (0~65°C) and a humidity accuracy of ±2%RH (10~90%RH, 25°C).

• Standard Industrial Interface: Uses an RS-485 communication interface and complies with the ModBus-RTU communication protocol, featuring strong compatibility and direct access to industrial systems such as PLC, DCS, and configuration software.

• Wide Voltage Power Supply: Supports DC 7~30V wide voltage input and has reverse connection protection, adapting to complex on-site power supply conditions.

• Industrial-Grade Reliability: Operating temperature range of -20~70°C, storage temperature range of -40~75°C, with excellent long-term stability (temperature <±0.03°C/year, humidity <±0.25%RH/year).

Technical Core and Communication Protocol Analysis

1. High-Precision Measurement and Resolution

• Sensor: Built-in high-precision integrated temperature and humidity sensing unit with fast response speed.

• Resolution: Temperature resolution of 0.1°C, humidity resolution of 0.1%RH, capable of detecting subtle environmental changes.

• Measurement Range: Temperature -20~70°C, humidity 0~100%RH (non-condensing).

2. Detailed Explanation of ModBus-RTU Communication

As a slave device in the ModBus network, this series of transmitters features flexible communication configurations:

• Device Address: Supports configurable addresses from 1 to 254, facilitating the connection of multiple devices on the same RS485 bus.

• Baud Rate: Supports multiple configurable baud rates (such as 1200, 2400, 4800, 9600, 19200, etc.), with a factory default of 9600bps.

• Parity Bit: Configurable as no parity, odd parity, or even parity, with a factory default of no parity.

• Communication Distance: Up to 2000 meters (requires compliant cables and may need repeaters).

3. Key Register Addresses (Holding Registers)

The device provides data and configuration through register mapping, with the main registers as follows:

Example Command (Reading Temperature and Humidity, Device Address 01)

• Host Send (Hex): 01 03 03 00 00 02 C4 4F

• Slave Reply (Hex): 01 03 04 01 0A 02 AF 9A D1

Analysis: 01 0A (hexadecimal) = 266 (decimal) => Temperature = 266 × 0.1 = 26.6°C
Analysis: 02 AF (hexadecimal) = 687 (decimal) => Humidity = 687 × 0.1 = 68.7%RH

Installation, Wiring, and Quick Start Guide

1. Product Interface and Wiring

The device uses a 4-wire terminal block:

• 1 (Red): VCC (Positive power supply, DC 7-30V)

• 2 (Black): GND (Negative power supply)

• 3 (Green): A (RS-485 signal line A+)

• 4 (Yellow): B (RS-485 signal line B-)

Note: The RS485 bus must be connected correctly with A/A+ and B/B-. It is recommended to connect a 120Ω terminal resistor in parallel at the end of the bus.

2. Quick Start Steps

1. Hardware Connection: Correctly connect the power supply and RS485 bus (connect to the computer via a USB-to-485 adapter).

2. Parameter Confirmation: Ensure that the device address, baud rate, and parity bit are consistent with the settings of the upper computer software (factory defaults: address 1, baud rate 9600, no parity).

3. Software Testing: Communication testing and data reading can be performed using software such as Modbus Poll, Modbus Scan, or EBYTE's dedicated "Temperature and Humidity Upper Computer" software.

4. Parameter Modification (Optional): If you need to modify the address, baud rate, etc., write new values to the corresponding registers (0x000C, 0x000D, 0x000E) through the software. The modification takes effect immediately.

Typical Application Scenarios

• Industrial Environment Monitoring: Temperature and humidity monitoring and recording in factory workshops and warehouses.

• Smart Agriculture: Environmental parameter collection in greenhouses, grain depots, and livestock farms.

• Smart Buildings: Control of air conditioning and fresh air systems in office buildings, shopping malls, and museums.

• Pharmaceutical and Food Industries: Environmental assurance in pharmaceutical warehouses, cold chain transportation, and food processing workshops.

• Data Centers: Precision environmental monitoring in computer rooms and server cabinets.

Introduction to EBYTE RS485 Temperature and Humidity Transmitter Product Line

EBYTE offers a rich variety of temperature and humidity transmitter products in the industrial sensing field to meet different installation methods and application requirements:

• Probe-Type Series (Focus of This Article): KTH2-R series, suitable for scenarios requiring the sensor to be inserted into equipment interiors, pipelines, or specific locations for measurement.

• DIN Rail Mount Series: KTH2-R (DIN rail housing), featuring standard DIN35 rail mounting and a compact size, suitable for centralized installation in power distribution cabinets and control boxes.

• Wall-Mounted/Ceiling-Mounted Series: Provides more installation options, suitable for environmental monitoring in rooms, halls, and other spaces.

• High-Precision/Wide-Temperature Series: Offers products with higher precision or wider operating temperature ranges for laboratories and special industrial environments.

• Multi-Function Composite Series: Transmitters integrating multiple sensors such as temperature and humidity, pressure, and carbon dioxide.

All EBYTE RS485 temperature and humidity transmitters comply with the ModBus-RTU standard protocol, feature industrial-grade design and high reliability, and can be seamlessly integrated into existing SCADA, PLC, or IoT platforms, providing users with stable and accurate environmental data sensing capabilities.