[spieswl]

Another thing to note is that, depending on the standards (e.g. NFPA vs IEC), your control diagrams would be in horizontal [0] or vertical [1] format. So the typical left-right ladder flow you might see in RSLogix or something worked really well with drawings produced to NFPA standards, but the mapping broke when given "waterfall"-like schematics from a European shop.

You are 100% correct about the tooling being crap and ladder representation being useful as a visual mapping.

[0] https://library.automationdirect.com/wp-content/uploads/2013...

[1] https://multilinedesigns.com/wp-content/uploads/2018/02/IEC-...

[MisterTea]

Ladder is completely unknown in most of Europe. I think it's mostly ST (structured text) followed by fbd (function block diagram) or sfc (sequential flow chart).

I'm not against st or c or whatever, I've done control programs in all of them. To me, Debugging ladder is awesome as most IDEs give you a live view of the io state and it's great to sit the laptop or computer cart by the machine and begin pressing switches and wiggling wiring/connectors to see what is not working and the ladder contacts light up when they go high. Simple fast visual debugging.

We've incorporated some flow chart and ladder like io debug screens on our hmi's. Pop open the debug screen and see what isn't on and the association of inputs and the output condition they set. Mostly eliminates the need to drag around the computer.