Introduction

Looking for a compact way to connect DS18B20 temperature sensors to an RS485 Modbus RTU network?

The Eletechsup N4DSB03 is a two-channel digital temperature acquisition module designed to read DS18B20 sensors and transmit temperature data to PLCs, HMIs, industrial computers, and embedded controllers.

Beyond the product specifications, the ElabNET Technik Forum provides an interesting third-party integration reference for this type of device. A community member shared a Modbus profile for the Eletechsup N4DSB03 and discussed a practical commissioning adjustment involving the Modbus response delay.

For engineers working with Modbus-based temperature monitoring, this is a useful example of how device configuration and communication timing can matter alongside the hardware itself.

Third-party technical discussion:
https://forum.timberwolf.io/viewtopic.php?t=5912

Official N4DSB03 product page:
https://eletechsup.com/products/n4dsb03-1-2ch-rs485-digital-temperature-collector-module-55-to-125c-ds18b20-sensor-dc-5v-12v-24v-for-thermostat-smart-home-r46ca01

1. N4DSB03: Two Temperature Channels in a Compact Module

The N4DSB03 is designed for applications that require two temperature measurement points using DS18B20 digital temperature sensors.

Key Technical Specifications

Parameter	Specification
Temperature sensor	DS18B20
Acquisition channels	2
Temperature range	-55°C to +125°C
Communication interface	RS485
Communication protocol	Modbus RTU
Supported function codes	03, 04, 06, 16
Supply voltage	DC 6–25V
Working current	Approximately 7–8mA
Default baud rate	9600 bps
Configurable baud rate	1200–115200 bps
Default serial format	8 data bits, no parity, 1 stop bit
PCB dimensions without terminals	32.6 × 25.8 × 3.5mm
PCB dimensions with terminals	32.6 × 25.8 × 12mm

Please refer to the official product documentation for the exact register map, wiring details, temperature scaling, and configuration commands for your hardware revision.

2. A Community Modbus Profile for N4DSB03

The ElabNET Technik Forum features a discussion titled “MODBUS PROFILE: 1-Wire DS18B20 to Modbus Converter N4DSB03.”

In this discussion, a community member shared a Modbus profile and configuration files for integrating the N4DSB03 with the Timberwolf Server environment.

This kind of device profile helps an automation system identify the Modbus registers to read and interpret the temperature measurements returned by the module.

For system integrators, community-created profiles can be useful starting points when connecting temperature acquisition hardware to an existing building automation or monitoring platform.

The profile is an independent community contribution, not an official Eletechsup software package. Its compatibility should be checked against the actual module, firmware, and master-controller configuration.

3. Practical Modbus RTU Troubleshooting: Response Delay

One useful detail from the forum discussion is the author's report that setting the response delay to more than 5 ms helped during commissioning.

This is worth considering when troubleshooting a Modbus RTU installation that has the correct slave address and serial settings but still experiences communication problems.

Possible causes of Modbus communication issues include:

• Response timing and inter-frame delays

• Incorrect baud rate or serial format

• RS485 A/B wiring polarity

• Duplicate slave addresses

• Incorrect register addresses or data formats

• USB-to-RS485 adapter or master-controller behavior

• Electrical interference or unsuitable bus topology

The reported delay adjustment is a troubleshooting reference, not a universal requirement for every N4DSB03 installation. The ideal timing depends on the Modbus master, interface hardware, software implementation, and network conditions.

4. Connecting N4DSB03 to a PLC, HMI, or PC

A typical system architecture is:

DS18B20 sensors → N4DSB03 → RS485 bus → Modbus master

The Modbus master may be a PLC, industrial computer, HMI, or embedded controller.

A practical commissioning workflow is:

1. Connect the DS18B20 sensors according to the official wiring diagram.

2. Supply the module with the correct DC voltage.

3. Connect the RS485 interface to the Modbus master.

4. Configure the slave address, baud rate, parity, and stop bits.

5. Read the documented temperature registers and verify the returned values.

6. If communication remains unstable, check wiring, timing, and the master's serial configuration.

The community profile can be used as a reference for compatible software environments, while the official N4DSB03 protocol documentation should remain the authority for register addresses and data interpretation.

5. Applications for Two-Point Temperature Monitoring

HVAC and Building Automation

Monitor two temperature points in heating, ventilation, and cooling equipment and transmit the readings to a compatible automation controller.

Refrigeration and Cooling Systems

Measure inlet and outlet temperatures to help operators track system behavior and identify unusual temperature differences.

Electrical Cabinets and Equipment

Monitor temperatures at two locations inside an enclosure and use the host controller to trigger alarms when configured limits are exceeded.

Industrial and Embedded Monitoring

Collect two DS18B20 readings at a remote location and transfer them to a central controller over an RS485 network.

In these applications, the N4DSB03 handles temperature acquisition and communication. Data logging, dashboards, alarm rules, and control actions are implemented by the host system.

6. Why Community Integration Examples Matter

Official product documentation describes hardware capabilities and protocol behavior. Independent community projects can add practical insight into how a particular device is configured within a real software environment.

The ElabNET discussion provides a useful reference for:

• A community-created N4DSB03 Modbus profile

• Integration with a building automation server

• Practical configuration and commissioning

• A reported response-delay adjustment during troubleshooting

These details can help developers plan their own integration and identify settings worth checking when communication does not work as expected.

Conclusion

The Eletechsup N4DSB03 combines two DS18B20 temperature inputs with RS485 Modbus RTU communication in a compact acquisition module.

The ElabNET Technik Forum discussion adds a third-party integration reference by documenting a community-created Modbus profile and a practical response-delay troubleshooting observation.

For engineers building PLC, HMI, building automation, or embedded temperature monitoring systems, the combination of official product documentation and community integration experience offers a useful starting point for implementation.

Explore the Eletechsup N4DSB03:
https://eletechsup.com/products/n4dsb03-1-2ch-rs485-digital-temperature-collector-module-55-to-125c-ds18b20-sensor-dc-5v-12v-24v-for-thermostat-smart-home-r46ca01

Read the ElabNET community discussion:
https://forum.timberwolf.io/viewtopic.php?t=5912

SEO Keywords

Eletechsup N4DSB03, N4DSB03 Modbus RTU, DS18B20 RS485 temperature module, two-channel temperature acquisition, Modbus temperature converter, Timberwolf Modbus profile, RS485 temperature monitoring, Modbus RTU response delay, PLC temperature monitoring, building automation temperature sensor, DS18B20 Modbus integration, industrial temperature acquisition.