---
title: "Modbus / Profibus / Profinet"
description: "Modbus, Profibus and Profinet are the three dominant industrial fieldbus and industrial-Ethernet protocols. Sonic-horn cycle controllers typically support at least one for integration with the plant DCS or PLC."
canonical_url: "https://sylio.co/glossary/modbus-profibus-profinet"
last_updated: "2026-06-28T02:29:28.458Z"
---

**Modbus**, **Profibus** and **Profinet** are the three dominant industrial fieldbus and industrial-Ethernet protocols. [Sonic-horn](/glossary/sonic-horn) [cycle controllers](/glossary/cycle-controller-sequencer) typically support at least one for integration with the plant [DCS](/glossary/dcs) or [PLC](/glossary/plc).

<table>
<thead>
  <tr>
    <th>
      Protocol
    </th>
    
    <th>
      Origin
    </th>
    
    <th>
      Layer
    </th>
    
    <th>
      Common use
    </th>
  </tr>
</thead>

<tbody>
  <tr>
    <td>
      <strong>
        Modbus RTU
      </strong>
    </td>
    
    <td>
      Modicon (1979)
    </td>
    
    <td>
      Serial RS-485
    </td>
    
    <td>
      Widely supported, low cost; common on legacy and smaller installations
    </td>
  </tr>
  
  <tr>
    <td>
      <strong>
        Modbus TCP
      </strong>
    </td>
    
    <td>
      Modicon
    </td>
    
    <td>
      Ethernet
    </td>
    
    <td>
      Modern Modbus over IP; easy integration
    </td>
  </tr>
  
  <tr>
    <td>
      <strong>
        Profibus DP
      </strong>
    </td>
    
    <td>
      Siemens / PNO
    </td>
    
    <td>
      RS-485
    </td>
    
    <td>
      Long-established in European process automation
    </td>
  </tr>
  
  <tr>
    <td>
      <strong>
        Profinet
      </strong>
    </td>
    
    <td>
      Siemens / PNO
    </td>
    
    <td>
      Industrial Ethernet
    </td>
    
    <td>
      Modern Siemens-led standard; high-performance
    </td>
  </tr>
</tbody>
</table>

## Specification practice

Specify the required fieldbus at RFQ stage to avoid post-installation gateway costs. Sonic-horn controllers from major vendors offer optional fieldbus interface cards; selecting at order is straightforward but field-retrofitting often requires returning the controller for upgrade.

## Related terms

- [PLC](/glossary/plc)
- [DCS (Distributed Control System)](/glossary/dcs)
- [Cycle controller / sequencer](/glossary/cycle-controller-sequencer)