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The 7Semi RS485 THAQ Probe is a high-performance, multi-parameter environmental sensor designed for precise monitoring of Temperature, Humidity, VOCs, and NOx-based Air Quality using the industry-standard RS485 Modbus RTU protocol.

Built around an advanced digital sensing core and engineered for stable long-term operation, this probe is ideal for HVAC automation, smart farming, industrial IAQ monitoring, environmental data logging, and weather/climate measurement applications.

It delivers high-resolution raw gas values along with calculated Air Quality Indices, allowing developers, integrators, and industrial systems to access both processed and raw environmental signals.

This version includes a 2-meter, features a wide 9–36V DC input range, Software configurable Modbus address and baud rate, and onboard signal processing. Fully plug-and-play with SCADA, PLCs, HMIs, and Arduino/MCUs.

Key Features

High-accuracy temperature & humidity
VOC & NOx-based air quality monitoring
RS485 Modbus RTU communication
Long-distance up to 1200m
Raw gas outputs + calculated IAQ indices
Industrial-grade performance
Fast response and low drift
Ideal for both indoor and outdoor applications
Ideal for PLCs, IoT gateways, data loggers, and SCADA

Wide Input Voltage: 9V–36V DC
Software Configuration for Modbus ID & Baud Rate
Easy 4-wire Connection: VCC, GND, RS485 A+, RS485 B−

Wiring Guide

Applications

Smart farming & greenhouse automation
IAQ monitoring for buildings & offices
Parking garage / tunnel air quality
VOC & NOx pollution monitoring
HVAC & AHU systems
Smart city environmental nodes
Industrial plant monitoring
Data logging & IoT gateways

Frequently Asked Questions (FAQ)

Q1: Is the sensor compatible with PLCs and SCADA systems?
Yes, the sensor uses RS485 with Modbus RTU, compatible with most industrial automation systems.

Q2: How do I read the sensor values?
Use Modbus function code 0x03 to read two 16-bit registers. Divide by 10 to get the actual values in °C and %RH.

Q3: How is the device configured?
You can set the Modbus address (1–255) and baud rate using Software software . Supported baud rates include 9600, 19200, 38400, and 115200.

Q4: Can I interface this with Arduino?
Absolutely. It includes a sample Arduino wiring and code setup using RS485 to TTL adapters.