What is a RS232 sensor ?

A RS232 sensor is an intelligent digital temperature sensor that integrates:

• a measuring element (RTD or thermocouple),
• a high-precision analog-to-digital converter,
• and a serial transmitter compliant with the RS232 ±12 V standard.

It can be connected directly to a PC COM port or to a USB–RS232 adapter for reading and recording.

Operating principle

The sensor measures the temperature through its sensitive element (often a Pt100 probe or type K thermocouple), and then converts the data into a normalized numerical value.

This data is transmitted in ASCII format or proprietary protocol via RS232.

Example of a typical frame:

T=024.63°C␍␊

💡 Each measurement is sent periodically (1 to 10 Hz) or on request.

Example of digital conversion (PC / Python)

import serial

ser = serial.Serial('/dev/ttyUSB0', baudrate=9600, timeout=1)
while True:
    data = ser.readline().decode().strip()
    if data.startswith("T="):
        temp = float(data[2:].replace("°C", ""))
        print(f"Température : {temp:.2f} °C")

✅ Example output:

Temperature: 24.63 °C

Principle diagram

[RS232 Sensor] ───── DB9 ─────► PC / Datalogger
         │
         └── Probe (Pt100, thermocouple, etc.)

💡 The RS232 cable can reach 15 meters without signal loss.

Application areas

🧪 Testing and Calibration Laboratories

🏭 Industrial Automation

⚙️ HVAC Supervision

🚚 Mobile Temperature Recorders

🧠 Embedded Systems with Direct Serial Communication