DNMPB28

 Eletechsup DNMPB28 is a multifunctional I/O expansion board designed for the Arduino MEGA2560 PRO platform. It combines analog signal acquisition, NPN/PNP digital inputs, relay outputs, MOSFET outputs, and RS485 communication, making it suitable for developers building customized monitoring and automation systems.

Its main advantage is integration: instead of assembling multiple separate modules, developers can use one board as the hardware foundation for a wide range of control applications.

Product link:
https://eletechsup.com/products/dnmpb28-dc-12-24v-multifunction-mega2560-pro-expanding-board-current-voltage-adc-collection-npn-pnp-isolated-di-relay-mos-do-for-arduino

1. Key Features and Advantages

16 Analog Input Channels for Different Signal Types

The DNMPB28 provides four channels for each of the following signal ranges:

• 4–20mA current input

• 0–100mA current input

• 0–5V/0–10V voltage input

• 0–30V voltage input

Key advantage: Developers can build multi-channel monitoring systems that handle different current and voltage signals on one platform.

Potential applications include pressure monitoring, liquid-level measurement, current monitoring, and voltage acquisition. Actual measurement performance depends on the connected instruments, calibration, wiring, and firmware.

NPN and PNP Digital Inputs

The board provides eight NPN and eight PNP digital input channels.

Key advantage: It offers flexibility when working with compatible sensors and switching devices that use different output configurations.

Typical applications include proximity sensors, limit switches, equipment status monitoring, and event detection.

Eight Relay Outputs and Eight MOSFET Outputs

The DNMPB28 combines two types of switching outputs.

Key advantage: Developers can select the appropriate output type for different control tasks rather than relying exclusively on relays or transistor outputs.

Possible uses include timed switching, power sequencing, pump-control circuits, and customized equipment-control logic. Output ratings and protection requirements must be checked before connecting actual loads.

RS485 Communication

The onboard RS485 interface supports the development of serial communication systems.

Key advantage: The board can combine local signal acquisition and output control with communication to compatible external equipment.

With appropriate firmware, developers can implement custom serial protocols or Modbus RTU applications. RS485 hardware alone does not provide a complete Modbus implementation.

Built-In Display and Buttons

The board includes a four-digit display, four buttons, and LED indicators.

Key advantage: Custom firmware can use these components to display measurements, countdowns, operating states, or alarm codes without requiring a separate user-interface module.

Arduino-Based Customization

The DNMPB28 is designed for use with a compatible MEGA2560 PRO controller.

Key advantage: Developers can adapt the control logic to their specific requirements, from simple relay timing to multi-channel monitoring and communication.

The board is an expansion platform rather than a standalone PLC. Application-specific programming is required.

2. Practical Application Examples

Example 1: Multi-Channel Industrial Signal Monitoring

Application environment: Equipment monitoring stations, engineering laboratories, and small automation systems.

A system may need to monitor several current-loop transmitters and voltage signals simultaneously. The DNMPB28 can provide the corresponding input interfaces for a customized acquisition program.

A typical solution could:

1. Read compatible current and voltage signals.

2. Convert readings into engineering values using calibration formulas.

3. Compare measurements with configured thresholds.

4. Display selected readings or transmit them through RS485.

5. Activate an output when a programmed condition occurs.

Main benefit: Multiple analog signal types can be handled on one integrated hardware platform, simplifying wiring and reducing the need for separate input modules.

Example 2: Water Tank and Pump Monitoring

Application environment: Water tanks, irrigation prototypes, and liquid-transfer systems.

A compatible level transmitter can provide a signal to the DNMPB28. The Arduino program can monitor the measured level and control a suitable pump-control circuit through an output.

Possible functions include high-level alarms, low-level alarms, automatic start and stop, and delayed switching to prevent rapid cycling.

Main benefit: Analog measurement, digital status monitoring, and relay control can be combined within one customized system.

For larger pumps or motors, use appropriately rated contactors and protection circuits rather than assuming the onboard relay can directly handle the load.

Example 3: Machine Status Monitoring

Application environment: Workshops, equipment test benches, and small automated machines.

Compatible proximity sensors and limit switches can be connected to the digital inputs. The Arduino firmware can monitor their states and trigger programmed sequences through the relay or MOSFET outputs.

Potential functions include detecting a machine state change, activating an indicator, starting a timer, or reporting an abnormal condition.

Main benefit: Developers can integrate input monitoring and multiple output types without assembling a separate module for each function.

The DNMPB28 is not a certified safety controller. Emergency stops and safety-critical functions require appropriate independent safety hardware.

Example 4: RS485-Connected Monitoring and Control

Application environment: Distributed equipment monitoring, test systems, and customized serial communication projects.

The DNMPB28 can acquire local signals and exchange information with compatible external devices through RS485 when suitable firmware is implemented.

Possible functions include transmitting measurements, receiving commands, reporting equipment status, and implementing Modbus RTU communication.

Main benefit: The same platform can support both local I/O operations and communication with other equipment, reducing the number of separate interface modules required.

Communication compatibility must be verified with the intended devices and protocol.

Example 5: Power Sequencing and Timer Control

Application environment: Electronics test benches, equipment startup systems, and automated switching panels.

The Arduino firmware can control the relay outputs according to programmed timing sequences.

For example, a project could switch several devices on in a defined order, introduce a delay between stages, or turn an output off after a configured interval.

Main benefit: Developers can combine multiple outputs and custom timing logic on one board rather than assembling a separate timer module for each stage.

The timing functions are implemented through software; they are not automatically available without programming.

3. Development Resources and Practical Considerations

Eletechsup's published product information lists demonstration programs for:

• RS485 data transmission and reception

• Analog acquisition combined with RS485

• NPN digital input and relay testing

These examples provide a starting point for validating the hardware interfaces before developing a complete application.

The manufacturer states that the supplied sketches are intended for hardware testing. More advanced application functions require additional Arduino programming.

Before deployment, developers should verify the controller compatibility, signal ranges, wiring, relay and MOSFET ratings, power supply requirements, and communication configuration.

4. Why Choose the DNMPB28?

The DNMPB28 is particularly attractive when a project requires several types of I/O in a single Arduino-based platform.

Its main benefits are:

• Hardware integration: Multiple signal interfaces are available on one board.

• Flexible signal acquisition: Different current and voltage ranges can be accommodated.

• Versatile control: Relay and MOSFET outputs support different switching approaches.

• Communication potential: RS485 provides a foundation for connected control systems.

• Local interaction: The display and buttons can support a customized interface.

• Programmability: Developers can build application-specific behavior using Arduino code.

These advantages make the board suitable for prototyping and customized monitoring systems. They do not imply that it is a ready-to-use industrial PLC or that every application is supported by prewritten software.

Conclusion

The Eletechsup DNMPB28 combines multi-channel analog acquisition, NPN/PNP digital inputs, relay outputs, MOSFET outputs, RS485 communication, and local display resources in one Arduino-based expansion platform.

Its strongest use cases include multi-channel monitoring, pump-control prototypes, machine status detection, RS485-connected systems, and programmable power sequencing.

For engineers, system integrators, educators, and makers who need flexible I/O hardware and are comfortable developing their own firmware, the DNMPB28 provides a versatile starting point for customized automation projects.

Explore the DNMPB28:
https://eletechsup.com/products/dnmpb28-dc-12-24v-multifunction-mega2560-pro-expanding-board-current-voltage-adc-collection-npn-pnp-isolated-di-relay-mos-do-for-arduino