A general-purpose professional input/output module based on Arduino

4 analog/digital inputs and 2 digital inputs, using robust protection circuits and dedicated operational amplifiers

6 top-quality power relays with double-winding latching bistable coils and one 0÷10V analog output

Power supply
Oversized, robust and efficient wide-range power supply

Main circuit board
A beautiful circuit board with widely spaced components and large tracks for power lines

Terminal blocks
Large terminal blocks with 0.15 inch pitch for all inputs and 12A rated, 0.2 inch pitch terminal blocks for power outputs

DIN standard case with omega-rail mounts

Iono is a work-suit for Arduino, it turns it into a PLC that combines the ease of use of the Arduino platform and the vast amount of software available for it with robust input and output electronic interfaces.

Iono can be employed both in industrial and residential environments, for professional applications where extreme reliability, ruggedness and compliance with technical and safety directives are required.

It is compliant with the 2014/35/UE (Low Voltage) and 2014/30/UE (EMC) CE directives, and the harmonised standards for electromagnetic compatibility (EN61000-6-2:2005), electrical safety (EN60664-1:2007), emission (EN61000-6-3:2007) as well as the RoHS directive for hazardous substances (2011/65/UE).

Iono Ethernet

includes Arduino Ethernet Rev 3


Iono Uno

includes Arduino Uno Rev 3 SMD


Iono Solo

add your own Arduino-compatible board
(certification still applies to the iono board and enclosure, without the controller board)


How to

Iono can be used in several ways:

As an armored Arduino

You can do anything you are able to do with an Arduino, in the same exact way, programming it with the standard Arduino IDE. You just have a more robust hardware that will help you transition from your prototipe to your final professional project.

As an Ethernet I/O module

Out of the box, Iono Ethernet includes a Web application and it is ready to be used as a simple Ethernet I/O module that you can control and configure through a nice Web interface and/or with a simple HTTP API.

As a Modbus module

Are you more at ease with Modbus devices? No problem, just upload the Modbus TCP or Modbus RTU sketches available from the libraries examples (or ask us to ship it to you with the sketch pre-installed) and your Iono turns into a standard Modbus module, configurable with a simple serial interface.

Of course, you can always modify the provided Web and Modbus sketches and add your custom logic!


Power Supply

The power supply stage is a heavily protected and filtered circuit, using oversized electrolytic capacitors, diodes and inductors, and a high efficiency voltage regulator. Iono accepts a wide power supply range, from 11 to 30 VDC or 11 to 21 VAC, and should be able to effectively handle substantial amounts of ripple, noise and supply voltage fluctuations, typical of automotive applications.
The iono module, including the Arduino Uno board, has a typical current consumption of less than 35 mA at 12V, making it a great choice where energy consumption is important.

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Iono has 4 analog/digital inputs and 2 digital inputs. These inputs are not directly routed to Arduino’s pins. We use a robust protection circuit with front-end operational amplifiers to safely feed these inputs with industry-standard 0÷10V voltage signals or 0÷20mA current loops. The same inputs can also be used as digital inputs.
The 2 dedicated digital inputs can be used for potential-free contacts, and are also protected with a current-limiting network and capacitive filtering.

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Power Outputs

Iono has 6 power relay outputs rated for 12A at 250V, which can tolerate large peak currents (inrush current) up to 80A. We use very large latching relays with rated load of 16A at 250V, up to 6,000 VAC dielectric strength between coil and contacts and 10 kV impulse withstand voltage.
These relays have a minimum mechanical durability of 5,000,000 operations and an ambient operating temperature between -40º and 85ºC. Being double-winding latching relays, the coils only draw current when the relay is switched, and no continuous current is required to keep the output closed. Latching relays are of course very expensive and the control logic is also complex, but they generate no heat and require no current when stable, dramatically improving the reliability and efficiency compared to output modules based on traditional relays.

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Analog Output

Iono has one analog output with a 0÷10V industry-standard range, controlled by a PWM output pin of the Arduino board. The variable voltage level is generated using a dedicated TSX561 operational amplifier that offers state-of-the-art accuracy and performance and is specifically suited for industrial signal conditioning and harsh automotive applications.
The result is a clean, stable voltage output and improved reliability.

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Mechanical Construction

Iono is housed in a DIN standard case with omega-rail mounts.The case is 9-modules wide, equivalent to 160.0mm. Using a large case allowed us to design a cleaner circuit board with properly spaced components, and oversized copper tracks. We can use large size discrete components for improved reliability and performance.
We also have room for large terminal blocks, using 0.15 inch pitch terminal blocks for all inputs, with separate tracks for the different analog input modes and multiple GND and common voltage tracks. The output terminal blocks are even larger, having a 0.2 inch pitch, rated at 12A continuous current.

Read more


Connection example

Quick Start

Iono Ethernet ships with our HTTP server sketch pre-installed (you can download the Iono Web Library from the downloads section for the details), and the following network configuration:


  1. Power up iono
  2. Gently remove the side cover on the inputs side
  3. Check that the LD1 power LED, next to the power supply terminals, is on
  4. Connect iono to your network and, using any modern Web browser from a device within the same network, go to
  5. Click the settings icon and enter your preferred network parameters and password, then press save
  6. You should now be able to access iono again using the newly assigned address


Iono Uno ships with a simple test sketch pre-installed. This sketch will simply intermittently glow the LD2 LED, that is associated to the AO1 analog output voltage level.

  1. Power up iono
  2. Gently remove the side cover on the inputs side
  3. Check that the LD1 power LED, next to the power supply terminals, is on
  4. Check that the LD2 LED, the one next to the AO1 analog output terminal block, constantly glows in on-off cycles of about 4 seconds
  5. Once you know that iono is working you will most likely want to load your own sketch to do something slightly more useful than glowing a LED. Check the downloads section for the iono base library and examples

Iono Solo doesn’t ship with a pre-installed sketch, for the simple reason that there is no Arduino module installed!

Still, before installing your own Arduino board, you should check that it powers-up normally.

  1. Power up iono
  2. Gently remove the side cover on the inputs side
  3. Check that the LD1 power LED, next to the power supply terminals, is on
  4. Remove the power supply
  5. Gently remove the side cover on the outputs side
  6. Install your Arduino board
  7. Reconnect the power supply and check that LD1 goes back on


Iono Base Library

The Iono base library includes a simple API to make it easier to read inputs and control the outputs of a iono module.
Because Iono is just a super-sized I/O shield for a standard Arduino 1.0 board, you can easily live without this library and simply control your Arduino I/O directly. The Iono Base Library and the Glow Sketch example program is pre-installed in our Iono Uno module.

Iono WEB Library

The Iono Web Library has been developed specifically for Iono Ethernet. It implements an HTTP-based API to control Iono over the network, but also includes a simple web client that allows you to easily control the outputs and check the inputs state from any modern Web browser.
The Iono Web Library and the WebApp Sketch example program are pre-installed in Iono Ethernet.

Iono UDP Library

The Iono UDP Library works on Iono Ethernet only.
It implements a very efficient API to control Iono over the network using the UDP protocol.



Any doubt? Please, read the Frequently Asked Questions