Introduction: Multi-Channel Temperature Monitoring Made Simple

Monitoring multiple temperature points simultaneously is essential in electronics testing, industrial automation, laboratory experiments, equipment diagnostics and product development.

When engineers need to measure temperatures at dozens of locations, using individual temperature meters can increase system complexity, equipment costs and data management workload.

The Eletechsup NT48C32 32-channel RS485 temperature acquisition module provides a practical alternative. Designed for NTC thermistor temperature measurement, the NT48C32 can acquire temperature data from up to 32 channels using a single module.

Even more interesting, an independent developer has created device definitions for the Eletechsup NT48 series for TestController, a PC-based measurement and data logging application.

This combination provides a useful starting point for building a multi-channel temperature data logging system.

Official product page:
https://eletechsup.com/products/nt48a08-nt48b20-nt48c32-32ch-rs485-temperature-collector-modbus-rtu-relay-board-for-ntc-sensor-inspection

1. What Is the Eletechsup NT48C32?

The NT48C32 is a 32-channel NTC temperature acquisition module with an RS485 interface and Modbus RTU communication protocol.

It is designed to measure temperature at multiple locations and transfer measurement data to a compatible controller, computer or industrial monitoring system.

Instead of installing 32 separate temperature meters, engineers can use one NT48C32 module to collect measurements from 32 NTC thermistors.

Key Technical Specifications

Specification	NT48C32
Temperature input channels	32
Communication interface	RS485
Communication protocol	Modbus RTU
Operating voltage	DC 7–25V
Operating current	Approximately 10–30mA, depending on connected NTC sensors
Recommended temperature sensor	10K B3950 NTC thermistor, 1%
Temperature measurement range	−20°C to +125°C with the recommended sensor
Specified temperature measurement accuracy	1% with the recommended sensor
Default baud rate	9600 bps
Other selectable baud rates	2400, 4800, 19200, 38400, 57600 and 115200 bps
Serial parity	None, even or odd
Supported Modbus function codes	03, 04, 06 and 16
PCB dimensions	Approximately 156 × 72 × 15mm
PCB weight	Approximately 56g

The temperature range and accuracy depend on the selected NTC thermistor and measurement conditions. The recommended NTC sensors are sold separately unless included in the selected package.

For complete technical details and the Modbus RTU command documentation, refer to the official Eletechsup product page.

2. Third-Party Software Integration: TestController

One of the most interesting developments involving the NT48C32 comes from the electronics community.

On February 10, 2026, an independent developer known as flash2b posted a discussion on Circuits Online announcing new TestController device definitions for three Eletechsup temperature acquisition modules:

• Eletechsup NT48A08 — 8-channel temperature acquisition

• Eletechsup NT48B20 — 20-channel temperature acquisition

• Eletechsup NT48C32 — 32-channel temperature acquisition

The developer specifically noted that the NT48C32 can log temperature data from 32 channels using a single module.

The discussion also mentions individual NTC thermistor calibration through the software's Setup menu and a Mode menu for resistance measurement.

On February 19, 2026, the TestController V2.96 update announcement listed the three NT48 models as supported device definitions.

These are useful independent software integration references for engineers who want to explore PC-based temperature measurement and data logging.

Read the original discussion:

https://www.circuitsonline.net/forum/view/message/2627441

Important: The device definitions were contributed by an independent developer. Users should verify the required software version, connection settings and device definition files before deploying the system.

3. What You Need to Build the System

To build a basic 32-channel temperature acquisition and data logging system, prepare the following components.

Hardware

1. Eletechsup NT48C32 temperature acquisition module

The main measurement device, capable of collecting data from up to 32 NTC temperature sensors.

2. Up to 32 compatible NTC thermistors

Use the recommended 10K B3950 NTC thermistors with 1% resistance tolerance for the specified temperature range and accuracy.

Select sensor probes appropriate for your application. Waterproof probes may be useful for certain environmental or equipment monitoring applications, provided their specifications suit the installation conditions.

3. A suitable DC power supply

The NT48C32 operates from DC 7–25V. Choose a regulated supply within this range and observe the correct polarity.

4. An RS485-to-USB converter

For direct connection to a computer, use a compatible USB-to-RS485 adapter.

The adapter allows the computer to communicate with the NT48C32 over its RS485 serial interface. Check the converter's driver requirements and wiring before connecting the system.

5. A computer running compatible TestController software

Install the appropriate TestController version and obtain the NT48C32 device definition from the developer's published resources.

Software

• TestController

• The compatible NT48C32 device definition

• An operating-system-compatible USB-to-RS485 driver, if required

• A serial-port configuration matching the NT48C32

• Optional spreadsheet or data-analysis software for further processing of exported measurements

4. Step-by-Step Setup Guide

Step 1: Connect the NTC Temperature Sensors

Connect each NTC thermistor to its corresponding input channel on the NT48C32.

For a complete 32-channel temperature monitoring system, assign a sensor to each of the 32 channels.

Consider labeling the sensors according to their physical locations, such as:

• CH01 — Power supply heatsink

• CH02 — Transformer surface

• CH03 — Enclosure interior

• CH04 — Ambient air

• CH05–CH32 — Other monitoring points

These labels are examples. Use the actual channel assignments and sensor wiring specified in the product documentation.

Clear labeling makes it easier to identify abnormal temperatures and compare readings across different parts of the equipment.

Step 2: Power the NT48C32

Connect a regulated DC power supply within the specified DC 7–25V operating range.

Before powering on, check the polarity, terminal assignments and wiring.

For installations involving industrial equipment, follow appropriate electrical safety procedures and keep sensor wiring away from sources of electrical interference where practical.

Step 3: Connect the RS485 Interface

Connect the NT48C32 to a USB-to-RS485 converter.

Connect the converter to the computer and install any necessary drivers.

Verify the RS485 terminal assignments and wiring polarity against the module documentation. Do not assume that every manufacturer's A/B terminal naming convention is identical.

For an initial test, use a short cable and a single module. This helps simplify troubleshooting before installing the system in its final environment.

Step 4: Configure Serial Communication

The NT48C32 uses Modbus RTU communication.

Its default baud rate is 9600 bps, with other selectable rates available. The serial parity can also be configured.

Start with the module's documented default settings. Ensure that the computer software, serial interface and module use matching communication parameters.

The Modbus device address must also match the configured address of the module.

Step 5: Load the TestController Device Definition

Install TestController and locate the device definition for the Eletechsup NT48C32.

The independent developer's discussion provides a reference for locating the relevant definition files:

https://www.circuitsonline.net/forum/view/message/2627441

Follow the installation instructions provided with the software and device definition. Menu names and installation procedures may differ between software versions.

Once the definition has been loaded, select the NT48C32 device and configure its communication settings according to the hardware documentation.

Step 6: Verify Temperature Readings

Before starting a long recording session, verify that the software communicates correctly with the module.

Check that:

• The correct serial port is selected.

• The baud rate and parity match the module settings.

• The device address is correct.

• The expected temperature channels are available.

• The readings are plausible for the connected sensors.

• The channel labels correspond to the actual sensor locations.

If communication fails, check the USB-to-RS485 driver, terminal polarity, power supply, serial settings and device definition.

Do not assume that a successful serial-port connection alone guarantees correct Modbus communication.

Step 7: Configure NTC Calibration

The developer's discussion notes that the NTC thermistors can be calibrated individually through the TestController Setup menu.

This is useful when different probes exhibit small measurement differences or when a project requires more consistent readings across multiple channels.

Use an appropriate reference thermometer or temperature standard and follow the software's calibration procedure.

Calibration should be performed under suitable, stable conditions. Record the calibration date and reference conditions if the measurements are being used for engineering validation or quality control.

Step 8: Start Temperature Data Logging

After communication and sensor readings have been verified, configure the desired recording interval and start collecting data.

A 32-channel temperature data logging setup can help engineers observe how temperatures change over time rather than relying on isolated measurements.

Depending on the software configuration and available export functions, recorded measurements may be used for trend analysis, comparisons between channels, test reports and further data processing.

Verify the actual logging interval, file format and export capabilities in your installed TestController version before designing a production workflow.

5. What Can You Do With a 32-Channel Temperature Logger?

The NT48C32 can be useful in a variety of engineering applications.

Electronics Testing and Thermal Analysis

Monitor temperatures at multiple points on a PCB, power supply, transformer, heatsink or electronic enclosure.

This can help engineers investigate temperature distribution and identify locations that require further thermal evaluation.

Industrial Equipment Monitoring

Monitor multiple temperature points in machinery, electrical cabinets and equipment enclosures.

The RS485 Modbus RTU interface provides a familiar communication method for compatible industrial data acquisition and control systems.

Laboratory Experiments

Record temperatures at different positions during experiments, prototype testing or material evaluation.

A multi-channel temperature acquisition module can reduce the number of separate measuring instruments needed for certain test setups.

Battery and Power Electronics Testing

Monitor multiple surface temperatures during controlled charging, discharging or power electronics experiments.

Use appropriately rated sensors, suitable electrical isolation where required, and independent safety protections for battery testing. The NT48C32 should not be treated as a safety shutdown device unless a complete system has been specifically engineered and validated for that purpose.

Environmental and Equipment Monitoring

Measure temperatures at multiple points within an enclosure, equipment room or test environment.

For installations exposed to moisture or other environmental conditions, verify the protection rating of the sensor probe, connectors and complete installation.

6. Why Choose 32 Channels Instead of Multiple Single-Channel Meters?

A single 32-channel temperature acquisition module can simplify the architecture of a multi-point measurement project.

Fewer separate measurement devices: One module can collect readings from up to 32 temperature inputs.

Centralized data acquisition: Measurements can be collected through a common RS485 communication interface.

PC-based monitoring: A compatible software environment can display and record multiple temperature readings.

Flexible integration: Modbus RTU is widely used in industrial automation and can be integrated into compatible controllers and software.

Expandable product choices: Eletechsup also offers the NT48A08 with 8 channels and NT48B20 with 20 channels, allowing engineers to choose a channel count closer to their requirements.

Actual cost savings depend on the number of channels, sensor requirements, wiring, software and installation costs.

7. Frequently Asked Questions

Q1: Can the NT48C32 monitor 32 temperature sensors simultaneously?

Yes. The module is designed for simultaneous temperature acquisition from up to 32 NTC sensor channels.

Q2: Does the NT48C32 support Modbus RTU?

Yes. It uses RS485 communication with the Modbus RTU protocol.

Q3: Can I connect the NT48C32 directly to a computer?

A compatible USB-to-RS485 converter is generally used for a direct computer connection. You must also configure the correct serial communication settings and use compatible software.

Q4: Is TestController officially developed by Eletechsup?

The cited device definitions were contributed by an independent developer. The forum discussion does not establish an official partnership between Eletechsup and TestController.

Q5: Can each NTC channel be calibrated separately?

The independent developer describes individual NTC calibration through the TestController Setup menu. Verify the procedure with the applicable software version and device definition.

Q6: Are NTC sensors included with the module?

The official product listing states that NTC sensors are sold separately unless otherwise specified in the selected package.

Q7: Can the NT48C32 measure resistance as well as temperature?

Yes. Eletechsup describes the NT48 series as supporting temperature measurement and resistance measurement. Refer to the official command documentation for supported measurement modes and limits.

Conclusion

The Eletechsup NT48C32 combines 32-channel NTC temperature acquisition with RS485 Modbus RTU communication in a compact measurement module.

The independent TestController device definition provides an additional reference for engineers interested in PC-based temperature monitoring, calibration and data logging.

For projects involving electronics testing, industrial temperature monitoring, laboratory measurements and multi-point thermal analysis, the NT48C32 is worth evaluating as part of a complete temperature acquisition system.

Explore the Eletechsup NT48 series:

https://eletechsup.com/products/nt48a08-nt48b20-nt48c32-32ch-rs485-temperature-collector-modbus-rtu-relay-board-for-ntc-sensor-inspection

Read the third-party software integration discussion:

https://www.circuitsonline.net/forum/view/message/2627441

Eletechsup — Practical RS485, Modbus RTU and industrial electronics solutions for engineers, developers and OEM projects.

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