Iono MKR

An industrial PLC powered by an Arduino MKR board

Iono MKR is a flexible and powerful controller built around the Arduino MKR series, using the SAMD21 32-bit ARM Cortex-M0+ low-power microcontroller. It integrates standard industrial interfaces along with analog and digital I/O, making it suitable for a wide variety of applications.

Programming Iono MKR is identical to working with any Arduino MKR board—you use the same development tools and environment, with full compatibility with Arduino libraries and community resources. There’s no need for additional drivers or proprietary code.

Thanks to the various wireless communication options available across the MKR lineup—such as WiFi, Bluetooth, GSM, NB-IoT, LoRa, or SigFox—Iono MKR is ideal for Internet of Things (IoT), telemetry, and remote control projects.

Designed for both industrial and residential installations, it ensures long-term stability, robustness, and full compliance with relevant safety and EMC regulations.

Iono MKR meets CE requirements for low voltage and electromagnetic compatibility, adheres to RoHS restrictions on hazardous substances, and is fully certified under FCC and IC standards.

Mounting:

• 3 modules DIN rail case
• power supply, serial and I/O connections on pluggable terminal blocks

Power supply:

• 12÷24 Vdc power supply, with surge and reverse polarity protection, and 1.1A resettable fuse

Arduino compatibility:

• all 3.3V Arduino MKR boards (WiFi 1010, ZERO, FOX 1200, WAN 1300, GSM 1400)

Inputs/Outputs:

• 4 x power relay outputs rated for 6A at 250V
• 4 x multi-mode inputs: digital or 0÷30V or 0÷20mA analog
• 2 x digital inputs or TTL level I/Os (1-Wire, I2C, Wiegand support)
• 1 x 0÷10V analog output

Communication:

• standard RS-485 interface to the Arduino serial pins, with electrostatic discharge protection
• WiFi/BLE/GSM/NB-IoT/LoRa/SigFox depending on installed Arduino MKR board

Factory-installed optionals:

• real time clock (RTC) with back-up battery
• earthquake sensor module

Power Supply

Iono MKR includes a robust and well-filtered power supply section, featuring oversized capacitors, diodes, inductors, and a high-efficiency voltage regulator capable of delivering up to 2.0A at 5V to power any Arduino MKR board, including the MKR GSM 1400.

It accepts a wide input voltage range (9 to 28 Vdc), offering excellent tolerance against ripple, noise, and voltage variations.

Inputs

The device offers 4 analog/digital inputs and 2 digital inputs, all protected through front-end amplifiers and conditioning circuits.

Analog inputs handle standard 0–10V or 0–20mA signals, while the digital inputs can support voltages up to 40V and are protected with current limiting and filtering.

Inputs can be configured as TTL-level bidirectional lines, making them compatible with 1-Wire, I2C, Wiegand, or other digital communication standards.

Each input includes protective components such as resistor networks and Schottky diodes to ensure safe operation.

Relays

There are 4 relay outputs rated at 6A/250V (15A peak), controlled by the Arduino MKR digital pins.

These relays offer at least 5 million mechanical operations and provide 5kV isolation between coil and contact, ensuring safe operation in harsh environments.

Analog Output

A single analog output supports a 0–10V range, driven by the onboard DAC and buffered with a precision TSX561 op-amp.

This setup delivers a clean and reliable analog signal, ideal for industrial automation tasks.

RS-485 Serial Port

The standard RS-485 interface is implemented using the Arduino MKR’s UART, with ESD and surge protection, and supports up to 115200 bps in half-duplex.

TX/RX line control is managed via an Arduino digital pin, and an optional termination resistor can be enabled via jumper J3.

Optional Features

Factory options include a real-time clock (RTC) with a backup battery (MCP79410 via I2C), ensuring timekeeping even during power loss, and an earthquake detection module (OMRON D7S), allowing programmable safety actions in response to seismic activity.