cheap discrete i/o via Modbus tcp or ethercat or other?

cheap discrete i/o via Modbus tcp or ethercat or other?

For what purpose?

You can use the GPIO of an Arduino.

If you need something permanent, you can look at WAGO and BECKHOF

Cheap is subjective.
Check out Turck BL20. https://www.youtube.com/watch?v=XmqVRhV_7_g

ive had good luck with advantech adam remote io.

Click PLC without a program actually makes a cheap Modbus IO

Cheap comes out expensive

Greetings,

Much will depend on how many I/O you will require, but you may want to consider Triangle Research and their embedded Ethernet PLCs A base unit starts at 8 in / 8 out and there are digital expansion boards available.

The controllers incorporate Modbus as a communications protocol for Ethernet and supports both Modbus server and Modbus client.

More information is available through the following link:

http://www.eternity-sales.com/tri-plc/tri-plc.htm

Disclosure - ESI is an authorized Triangle Research distributor.