Ether-S-I/O (esio)

The Ether-S-I/O protocol is used for data transfer between PLCs (Programmable Logic Controller) and remote input/output devices (RIOs) manufactured by Saia-Burgess Controls Ltd. A "Smart remote input/output station (Smart RIO)" features physical inputs and outputs and contains a CPU on which a small application can be run. The inputs from these RIO stations can be read and written by the master station (a PLC) using the Ether-S-I/O protocol. The application which can be run on the RIO station is uploaded to the RIO station using the EtherSBus protocol.


The Ether-S-I/O protocol has been developed together with a new hardware of RIO devices. The advantages of this new protocol are to following:

  • A telegram can contain data for several remote I/O stations (it can be sent as IP broadcast and contains several sections, each of them for a destination station.
  • The full length of the datagram can be used (while Ether-S-Bus telegrams are limited in the size)

Protocol dependencies

Ether-S-I/O uses UDP as its transport protocol. The port used by Ether-S-I/O is 6060.

Example traffic



The Ether-S-I/O dissector is in preparation.

Preference Settings

There are no preference settings for the esio dissector.

Example capture file

Display Filter

A complete list of Ether-S-I/O display filter fields can be found in the display filter reference

Show only the Ether-S-I/O based traffic:


Capture Filter

You cannot directly filter Ether-S-Bus protocols while capturing. However, you can filter on the UDP port used.

Capture only the Ether-S-I/O traffic over the default port (6060):

 udp port 6060 

External links


Imported from on 2020-08-11 23:13:54 UTC