Modbus RTU & TCP/IP · Made in Italy

Modbus RTU & TCP/IP I/O modules and relay boards for industrial automation

Built for OEMs and system integrators who need to integrate more I/O in less time, with a robust, well-documented board ready for the field.

● Made in Italy (CTA Electronics) ● Modbus RTU (RS485) and Modbus TCP/IP (Ethernet) ● Average lead time: 2 weeks (DRO)

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Share your required I/O and context (PLC/controller). We'll reply with a proposal and lead time.

Reliable I/O boards with digital and analog inputs and outputs for industrial applications

Selio I/O

RS485 · Ethernet

Made in Italy (CTA Electronics) Modbus RTU (RS485) and Modbus TCP/IP (Ethernet) Average lead time: 2 weeks (DRO) Modbus RTU & TCP/IP 8 · 16 · 24 I/O Industrial Grade

01 Designed and manufactured in Italy

Used to automate products, machines, lines and processes

Selio boards are adopted across multiple industrial applications to manage signals and actuation reliably.

02 Applications

Selio is a good fit if you…

01 are building a machine and want to reduce wiring and I/O complexity
02 need to integrate I/O with standard PLCs or custom controllers via Modbus RTU or Modbus TCP/IP
03 want a scalable base for machine variants (more modules, more I/O)

Typical uses

relay actuation (solenoid valves, pumps, lighting, drives, actuators)

Deploy

signal acquisition (sensors, statuses, temperature/pressure depending on model)

03 Benefits

Benefits

Faster time-to-market

Modbus RTU and TCP/IP plus onboard I/O means fewer separate components, simpler integration and fewer commissioning cycles. Integration time reduced by up to 60% where stated.

Field reliability

Opto-isolated digital inputs for noise immunity and industrial-grade design for continuous operation.

Simple scalability

Choose the right size (8 / 16 / 24 relays) and expand I/O consistently across the project.

04 Specifications

Technical features (at a glance)

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Download datasheet / documentation

Modbus RTU (RS485) and Modbus TCP/IP (Ethernet)

Opto-isolated digital inputs (AC/DC)

Analogue inputs (8 or 12 bit)

Relay outputs for industrial loads/actuation

Analogue outputs (voltage/current)

On-board functions (model dependent): buzzer, pressure sensor

05 Choose the relay density and I/O mix you need:

Choose the relay density and I/O mix you need:

Selio 8 — compact projects / retrofits

Selio 16 — a strong balance for many machines

Selio 24 — high-density I/O for complex automation

Compare Selio 8 / 16 / 24

06 Use case: industrial washing automation

"Selio 24 to drive valves, pumps, drives and monitor process variables."

View more use cases →

07 — Hardware

FAQ Support

FAQ

Is it compatible with my PLC/controller?

Selio supports Modbus RTU over RS485 and Modbus TCP/IP over Ethernet. If your system supports either protocol, integration is straightforward.

How long does commissioning take?

With communication and I/O integrated, commissioning complexity is reduced. (Integration time reduced by up to 60% where stated on site.)

Why is the price higher than budget options?

Selio is engineered for industrial use: you're paying for ruggedness, build quality and technical support. We'll help you select the right model without overspecifying.

What's the lead time?

Average lead time: 2 weeks (DRO).

Can you help me choose the right model?

Yes — in a technical call we define I/O, loads, Modbus mapping and your system context.

Get started

Ready to estimate cost and timing for your project?

Request a quote — we'll reply with a proposal, availability and technical guidance.

Request a quote Book a technical call

Optional: attach your I/O list, wiring diagram, or Modbus requirements.

08 From design to manufacturing, Selio I/O is entirely Made in Italy.

From design to manufacturing, Selio I/O is entirely Made in Italy.

A reliable family of electronic I/O boards with relays, designed and produced respectively by the Engineers and the Assembly Experts of CTA Electronics.