I just got my feet wet with an s7-1200 and I could not have imagined how horrible the programming of a PLC is. I spent a day just to get the plc send out UDP packets at 25Hz.

Apparently going above 10Hz is not really supported so you have to do silly tricks. I ended up running the send command on every tick, and running a time triggered cycle that toggles a bit at 50Hz and then using the rising edge of that bit to actually start the secretly async task of sending 20 bytes on the wire.

Son far I have learnt that async tasks are hidden, memory is measured in Kb, there is no guarantee for cycle time whatsoever, the programming model is really awkward, lots of config cannot be stored as code, version control is a bolted on nightmare, etc, etc.

Really makes me wonder what a PLC can do that an arduino/esp32/rp2040 can not. I'm really struggling to see the value other than that the hardware is reliable and "industrial".