Industrial automation is evolving beyond traditional PLC-based control systems. Today, engineers and developers increasingly combine remote I/O hardware, Ethernet connectivity, and software tools such as Python to build flexible monitoring and control solutions.

The Eletechsup 25IOB16 is a 16-channel digital input and output module designed for RS485 Modbus RTU communication. With PNP transistor outputs, it provides a practical option for projects that require digital signal acquisition and control of compatible DC loads.

An independent GitHub project demonstrates how the 25IOB16 can be integrated into a Python-based automation setup using PyModbus and an RS485-to-Ethernet gateway from Waveshare.

This combination illustrates how standard industrial communication protocols can connect remote I/O hardware with network-based applications.

1. A Flexible 16-Channel Remote I/O Module

The Eletechsup 25IOB16 combines digital inputs and PNP transistor outputs in one module.

Key features include:

• 16 digital inputs for monitoring external signals

• 16 PNP transistor outputs for controlling compatible DC loads

• RS485 communication using the Modbus RTU protocol

• Optically isolated digital inputs

• Multiple output control modes, depending on the supported commands and configuration

The PNP output design makes the module suitable for control systems that use sourcing transistor outputs and compatible input circuits.

Unlike mechanical relay outputs, transistor outputs are electronic switching devices. They can be useful in applications involving frequent switching, provided the load voltage, current, and electrical characteristics remain within the module's specifications.

2. Python and PyModbus Integration on GitHub

Open-source software can help engineers connect industrial hardware to custom applications.

The GitHub project WAVESHARE_RS485_ETH_Pymodbus_Eletechsup demonstrates a setup involving the Eletechsup 25IOB16, Python, the PyModbus library, and a Waveshare RS485-to-Ethernet gateway.

In this architecture, the remote I/O module communicates over RS485 using Modbus RTU. The gateway provides a network interface, allowing a compatible application to communicate with the serial device through Ethernet.

Python and PyModbus can then be used to develop custom logic for reading digital inputs and controlling supported outputs.

GitHub project:
https://github.com/ismaelit/WAVESHARE_RS485_ETH_Pymodbus_Eletechsup

The project is an independent developer example rather than an official Eletechsup software package. Users should check the repository's code, communication settings, and hardware configuration before adapting it to their own systems.

3. From RS485 Devices to Ethernet-Based Automation

Many industrial devices use RS485 because it is suitable for communication over practical cable distances and supports multidrop serial networks.

However, applications running on computers, servers, or network-connected controllers often need Ethernet access.

An RS485-to-Ethernet gateway can bridge these two environments.

A typical system architecture looks like this:

Python Application → Ethernet Network → RS485-to-Ethernet Gateway → RS485 Modbus RTU → Eletechsup 25IOB16

This approach can help developers explore:

• Network-based remote I/O control

• Centralized monitoring from a PC or server

• Custom Python automation scripts

• Integration with compatible supervisory software

• Distributed control systems using standard Modbus communication

The exact communication method depends on the gateway configuration. For example, a gateway may provide transparent serial tunnelling or a specific Modbus TCP-to-RTU conversion mode. These modes are not interchangeable in every configuration and should be verified before deployment.

4. Potential Applications

Industrial Monitoring

Read digital signals from compatible sensors, switches, and equipment status contacts, then process the data in a Python application.

Machine and Equipment Control

Use PNP transistor outputs to control compatible DC loads, such as suitable indicator devices or interface circuits.

Ethernet-Based Remote I/O

Connect a remote I/O module to a networked computer through a suitable gateway, enabling control from a central application.

Custom Test Systems

Develop Python scripts to automate input monitoring, output switching, and repeatable test sequences.

Industrial IoT Prototypes

Use standard Modbus communication as a foundation for integrating physical I/O into custom dashboards, logging tools, and higher-level automation applications.

These are potential applications. Actual suitability depends on the electrical requirements, communication configuration, and software implementation of the complete system.

5. Why Python-Based Industrial I/O Matters

Python offers developers a flexible environment for building automation logic, processing data, recording events, and connecting different software components.

When paired with a Modbus-compatible remote I/O module, it can provide a practical alternative for projects that do not require a full conventional PLC system.

The 25IOB16 can serve as the physical I/O layer, while Python handles application-specific logic. An Ethernet gateway can extend that architecture to network-connected systems.

This modular approach allows engineers to choose their own software environment and expand their systems according to project requirements.

6. Why Consider the Eletechsup 25IOB16?

For engineers selecting remote I/O hardware, important factors include channel count, output type, communication protocol, electrical compatibility, and ease of integration.

The 25IOB16 brings 16 digital inputs, 16 PNP transistor outputs, and RS485 Modbus RTU communication together in one module.

Its appearance in an independent Python and Ethernet-gateway project also provides a useful example of how the hardware can be incorporated into a customized automation architecture.

For developers who want to combine standard industrial I/O with Python-based control and network connectivity, the 25IOB16 is a product worth evaluating.

Conclusion: Connect Industrial I/O with Your Own Software

The Eletechsup 25IOB16 provides a flexible foundation for projects requiring digital input acquisition and PNP transistor output control over RS485 Modbus RTU.

Combined with a suitable RS485-to-Ethernet gateway and Python's PyModbus library, it can be explored in network-connected monitoring and automation systems.

The independent GitHub project demonstrates one practical integration approach and gives developers a starting point for building their own solutions.

Eletechsup — Practical RS485 Remote I/O Solutions for Industrial Automation and Custom Development.

Product information:
https://eletechsup.com/products/25ioa08-25iob16-25ioc32-8-32-di-do-pnp-to-pnp-rs485-modbus-rtu-remote-io-module-dc-12-24v-300ma-dmos-pnp

GitHub project:
https://github.com/ismaelit/WAVESHARE_RS485_ETH_Pymodbus_Eletechsup