There is also MQTT integrating bus-hardware- you basically plug in as bus-hardware replacement which allows to send data directly from the bus to the broker. The PLC never know what hit it.

https://www.ifm.com/de/de/product/AL1332

Pretty wild times.

PS: You can web GET/POST set and get ios with these. Robot experience that tragic irony POST {NOOO} and he just dropped it like its hot.